Gels including bioactive components

ABSTRACT

An ester-terminated dimer acid-based polyamide may be blended with a solvent to form a gel. The solvent may be flammable, and a wick may be added to the resulting gel so as to form a candle. Depending on the composition, the candle may be formed into a free standing pillar, or may be better suited to being placed in a container. The solvent may be mineral oil. A solid coating may be placed around the candle, for advantages including to enhance the clarity and/or mechanical stability of the gelled body, and to eliminate the tendency of a gel to have an oily feel and to accept noticeable fingerprints. The ester-terminated dimer acid-based polyamide may also be combined with an active ingredient, such as a fragrance, colorant, insect-repellant, insecticide, bioactive ingredient or the like, to afford a delivery vehicle for the active ingredient.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation under 35 U.S.C. 111(a) ofInternational Application PCT/US97/18821 with an international filingdate of Oct. 18, 1997; which is a continuation of U.S. application No.08/734,523, filed Oct. 18, 1996, now U.S. Pat. No. 5,783,657 andcontinuation of U.S. application No. 08/939,034 filed Sep. 26, 1997, nowU.S. Pat. No. 6,111,055, which applications are incorporated herein byreference in their entirety.

TECHNICAL FIELD OF THE INVENTION

The invention relates to gelled articles, and in particular to articlesthat are flammable, such as a candle, and/or contain an activeingredient, such as fragrance, where the article may include an exteriorcoating.

BACKGROUND OF THE INVENTION

A common type of candle that see widespread use consists of a wickembedded in a block of paraffin wax, where the wax provides the fuel forthe burning candle. Paraffin has many properties that make it suitablefor use in a candle. Paraffin as used in candles is typically highlyrefined and, at room temperature, is in a crystalline state. Crystallineparaffin is naturally white, and white paraffin candles are commonplace.Colorants may be added to these paraffin-based candles, to therebyachieve essentially any desired coloration. Paraffin-based candles arealso rigid, and can be formed into a free-standing pillar structure.Such pillar candles, whether white or colored, can be placed atopcandlesticks and the like, and are a popular consumer item. Paraffin isan inexpensive raw material, which makes it an economically-attractiveingredient for a candle. Perhaps unappreciated by consumers is thatparaffin is also a good material from which to prepare a candle becauseit meets the rather stringent burning requirements for a candle, asdiscussed in more detail herein.

Paraffin-based candles have a significant drawback, however.Paraffin-based candles are neither transparent nor translucent, and infact are opaque. Candle manufacturers have recognized an unmet need fortransparent candles, and particularly transparent candles which canadopt the pillar form, i.e., are rigid and self-supporting. Thus, theliterature describes numerous attempts to prepare a satisfactorytransparent pillar candle.

One approach has been to combine a thermoplastic polyamide resin with asolvent, where the polyamide resin is formed from dimer acid and acts asa gellant. Examples of this approach are found in, for example, U.S.Pat. Nos. 3,615,289; 3,645,705; 3,819,342 and 4,449,987. Candles made bythis approach, which may be referred to as polyamide gel candles, havesignificant shortcomings which have limited their commercial acceptance.For example, such compositions are often not very transparent or eventranslucent, and may require the addition of a “clarifying agent” toachieve even a semi-transparent state (see, e.g., U.S. Pat. No.3,819,342). In addition, such compositions are often not as hard asdesired, and may require additives that increase stiffness and hardnessin order to achieve even a short pillar form (see, e.g., U.S. Pat. No.3,645,705), or are simply recommended for use in containers (see, e.g.,U.S. Pat. No. 3,819,342).

Another significant problem with candles prepared with polyamidegellants is that they typically exhibit syneresis, where this termrefers to the formation of liquid on the surface of a gel or colloidalsuspension. In other words, droplets of solvent or other candle additiveoften form on the surfaces of a polyamide gel candle. Syneresis is ahighly undesirable property in a candle because, among other reasons, 1)consumers don't want to touch a wet, oil candle; 2) the candle becomesmore brittle as oil escapes; and 3) the droplets of liquidsolvent/additives tend to burn quite quickly once the candle is lit,giving the candle a torch-like quality.

Syneresis is particularly pronounced when the candle incorporatesfragrance: the fragrance is frequently observed to exude from the candleand exacerbate the flaring problem (as discussed in, e.g., U.S. Pat. No.3,615,289). Thus, for example, U.S. Pat. No. 3,645,805 suggests usingonly a small amount of fragrance in a polyamide gel candle, while U.S.Pat. No. 3,615,289 recommends up to about 2 percent fragrance. Whenrelatively high amounts of fragrance are incorporated into either apolyamide gel candle or the block copolymer gel candles discussed below,the fragrance is typically observed to separate from the candle matrixand pool on the top of the candle. This segregation of the fragranceleads to a flaring or flashing problem with gelled fragranced candles,so that these candles tend to burn in an “out of control” manner, whichthe prior art has yet to solve. Polyamide gel candles also tend toexhibit blooming, where this term identifies the formation of opaqueregions on the candle's surface. Blooming causes a significant aestheticdefect (opaque regions) in a candle that is supposed to be transparent.

Basically, the phenomena of syneresis and blooming reflect the fact thatthe components of a polyamide gel candle are not sufficiently compatiblewith one another to maintain a homogeneous state. The prior art has bothrecognized this problem and attempted to solve it by various means. Twosuch approaches are the judicious choice of solvent (see, e.g., U.S.Pat. No. 3,819,342), and/or including additives in the candlecomposition, such as “anti-flaring” compounds (see, e.g., U.S. Pat. No.3,615,289). These approaches have not been very successful in providinga candle which is desired by the public.

There are several other problems associated with the gel candlesprepared with polyamide gellants. One such problem is the failure of thecandle to have and/or retain a completely colorless clear appearance.More specifically, it is observed that these gel candles will typicallydevelop an undesirable yellow hue over time and/or with burning. Anotherproblem is that when a colorant has been added to a polyamide gelcandle, the initial color of the candle can fade, possibly due to areaction between the organic components of the candle and the colorant.Also, polyamide gel candles are often observed to form an irreversiblycrosslinked structure, which is undesirable because once the moltencomposition is poured into the form of a candle, it cannot be remeltedand repoured in instances where the original candle contained astructural defect.

In general, polyamide gel candles have serious shortcomings, and havenot received wide commercial acceptance. An alternative approach topreparing a clear gel candle is to disperse block copolymers in a clearoil, where a preferred block copolymer is a rubber. Disclosures of thisapproach are found in, for example, U.S. Pat. No. 3,578,089 and PCTInternational Application No. PCT/US96/13993. According to the '089patent, at least two components selected from the group consisting ofdiblock copolymers, triblock copolymers, radiai copolymers, multiblockpolymers and mixtures thereof may be used in combination withhydrocarbon oil to form a gel candle. PCT/US96/13993 is also directed tothe use of various block copolymers, preferably thermoplastics rubbers,in combination with mineral oil to form a gel suitable for molding intoa candle. Candles prepared by these technologies purportedly overcomemany of the problems observed with polyamide gel candles.

However, the '089 patent mentions that while the candle may be freestanding at room temperature, this patent also recommends that thecandle is preferably supplied in a container. The '089 patent commentsthat a container is desirable because of the gel-like nature of thecandle itself and its potential flowability when heated. The gel-likenature of the block copolymer candles is similar to the gel-like natureof the polyamide candles discussed above in that while a “free-standing”structure may be formed from each of these gels, such structures are“free-standing” only in the sense that Jell-O™, a well-known gelled foodproduct, is free-standing. Thus, a portion of Jell-O™ may be placed on aplate will maintain itself at some height above the plate, without beingcontained. In this sense, Jell-O™ and prior art gels are indeedfree-standing. However, consumers desire candles with a free-standingpillar structure, and while such a structure might be made from amaterial with the consistency of Jell-O™, it would only precariouslyhold the pillar structure—one little tap and the pillar would flop over.

While the prior art has attempted to increase the rigidity of a gelcandle (see, e.g., methyl esters as a stiffness additive as disclosed inU.S. Pat. No. 3,645,705), these attempts have either failed to providethe desired rigidity or have hurt other properties such as clarity,freedom from syneresis, and self-perpetuating flame. For example,attempts to increase the rigidity of a gel candle may take an approachthat causes a concomitant increase in the viscosity of the molten gel. Amore viscous molten gel will tend to incorporate and retain more airbubbles. The presence of air bubbles in a cooled candle will cause thecandle to have a translucent, rather than the desired transparentappearance.

Another reason why gel candles are often recommended for use incontainers as opposed to being free-standing is due to the potentialflowability of a gel candle when it is heated. Thus, when a prior artgel candle prepared from block copolymers is lit, the present inventorshave observed that the melted gel runs over the sides of the candle andonto the supporting table, which is commercially undesirable. Thepresent inventors speculate that this may be due to the thermal transferwithin the candle material. Thus, the high temperature near the flameand wick of a gel candle is rapidly and efficiently transferredthroughout the candle, so that the entire surface becomes heated aboveits melted point, producing too much melted candle. In any event,potential flowability issues associated with a gel candle can be avoidedby placing the candle in a container, which is the approach oftenrecommended in the prior art.

The use of a container is also desirable because of the problem ofseparating a gel candle from a mold. The thermoplastic polyamides thathave been used in the prior art to form gel candles are often alsouseful as adhesives. And the block copolymers that have been used toform gel candles are rubbers which are very sticky when molten and/orwhen mixed with oils. Thus, the gel candles of the prior art are noteasily removed from a mold (demolded), but instead may hold ontenaciously to the mold and be freed only with concomitant disfigurationof the surface of the candle. This disfiguration greatly reduces thecandle's clarity which is a primary object of the use of a gel candle.

Therefore, and despite significant attention, there remains an unmetneed in the art for a clear, free-standing, rigid and fragranced candle.The present invention provides a gel structure which is well suited forthe preparation of a clear candle. In addition, the gel structure of thepresent invention may incorporate various active ingredients, such asfragrance, which can be emitted from the gel over a sustained period oftime, thus providing a fragrant article such as a candle or airfreshener. These and other related advantages of the present inventionare disclosed below.

SUMMARY OF THE INVENTION

Briefly stated, the present invention provides a flammable article whichincludes a fuel and a solid coating, where the coating encases at leasta portion of the fuel. The article may further contain a wick, where thewick is at least partially encased within the fuel. The fuel may be awax or a gel. One fuel which may be used in the flammable articleincludes about 80 to 99 wt. % of a hydrocarbon oil, and about 1 to 20wt. % of a blend of at least two different polymer members selected fromthe group consisting of diblock copolymers, triblock copolymers, radialblock copolymers and multiblock copolymers, said composition includingat least one diblock copolymer and at least one triblock copolymer, withsaid diblock and triblock polymers comprising segments of styrenemonomer units and rubber monomer units. In another embodiment, the fuelincludes from about 70% to about 98% by weight of a hydrocarbon oil,from about 2% to about 30% by weight a copolymer selected from the groupconsisting of a triblock, radial block and multiblock copolymer, andfrom 0 to about 10% by weight of a diblock copolymer.

Preferably, the fuel is entirely a gel, where the gel is formed from agellant and a flammable solvent. The solvent preferably has a flashpoint ranging from about −15° C. to about 300° C. A preferred solvent ishydrocarbon oil, and a preferred article is a candle. Suitable gellantsare one or more of a polyamide resin, an ester-terminated dimeracid-based polyamide (ETDABP) resin and a block copolymer. The polyamideresin is preferably the reaction product of reactants including dimeracid and diamine. The ester-terminated dimer acid-based polyamide resinis preferably the reaction product of reactants including dimer acid,diamine and monoalcohol. The block copolymer is preferably astyrene-butadiene-styrene or styrene-isoprene-styrene block copolymer.

The coating on the article is preferably a polymer selected fromthermoplastic polymer and thermoset polymer. A suitable thermoplasticpolymer is selected from polyamide resin, ester-terminated dimeracid-based polyamide resin and styrene-acrylic resin. The coating ispreferably transparent, and in fact the fuel is also preferablytransparent. The article may further contain an optional componentselected from colorant, fragrance, insect repellent, insecticide,UV-inhibitor and antioxidant, where any of these optional components maybe present in the fuel and/or coating.

The invention also provides a flammable article formed from componentsthat include a gel, where the gel is formed from components including agellant and a flammable solvent, where the gellant includesester-terminated dimer acid-based polyamide (ETDABP). This gel in thisarticle is preferably one or more of transparent, rigid, free fromsyneresis, and free-standing or positioned within a container.Preferably, the article also includes a wick, the wick at leastpartially encased by the gel, where such an article is a candle. Thesolvent for the candle preferably includes mineral oil. The ETDABPcontributes 10-95%, and the solvent contributes 5-90% of the combinedweight of the ETDABP and the solvent in a preferred article.

Optional components selected from fragrance, colorant, insect repellent,insecticide, antioxidant and/or UV-inhibitor may be present. In apreferred article, the ETDABP contributes 30-60%, the solventcontributes 40-70%, the fragrance contributes less than 50% and thecolorant contributes less than 5% of the combined weight of the ETDABP,solvent, fragrance and colorant. In another preferred article, theETDABP contributes 10-30%, the solvent contributes 65-80%, the fragrancecontributes less than 50% and the colorant contributes less than 1% ofthe combined weight of the ETDABP, solvent, fragrance and colorant. Inpreferred ETDABPs, there is an amide:ester ratio of from 9:1 to 1:1.

The ETDABP in the above-described articles preferably has the formula(1):

wherein,

n designates a number of repeating units such that ester groupsconstitute from 10% to 50% of the total of the ester and amide groups;

R¹ at each occurrence is independently selected from hydrocarbyl groups;

R² at each occurrence is independently selected from a C₂₋₄₂hydrocarbongroup with the proviso that at least 10% of the R² groups have 30-42carbon atoms;

R³ at each occurrence is independently selected from an organic groupcontaining at least two carbon atoms in addition to hydrogen atoms, andoptionally containing one or more oxygen and nitrogen atoms; and

R^(3a) at each occurrence is independently selected from hydrogen, C₁₋₁₀alkyl and a direct bond to R³ or another R^(3a) such that the N atom towhich R³ and R^(3a) are both bonded is part of a heterocyclic structuredefined in part by R^(3a)—N—R³¹ or R³—N—R^(3a).

In preferred embodiments, the ETDABP of formula (a) has R¹ at eachoccurrence being independently selected from an alkyl or alkenyl groupcontaining at least 4 carbon atoms; R² at each occurrence beingindependently selected from a C₁₋₄₂ hydrocarbon group with the provisothat at least 50% of the R² groups have 30-42 carbon atoms; and R^(3a)at each occurrence being independently selected from hydrogen,C₁₋₁₀alkyl and a direct bond to R³ or another R^(3a) such that the Natom to which R³ and R^(3a) are both bonded is part of a heterocyclicstructure defined in part by R^(3a)—N—R³, such that at least 50% of theR^(3a) groups are hydrogen. Preferably, ester groups constitute from 20%to 35% of the total of the ester and amide groups.

In another preferred embodiment, R¹ in formula (1) is a C₁₂₋₂₂alkylgroup and R² is a C₃₀₋₄₂ hydrocarbon group having the structure ofpolymerized fatty acid with the carboxylic acid groups removed. In stillanother preferred embodiment, between 1% and 50% of the R² groups are aC₄₋₁₉ hydrocarbon group, R³ is a C₂₋₃₆ hydrocarbon group and R^(3a) ishydrogen. In still another preferred embodiment, R^(3a) is hydrogen andat least 1% of the R³ groups are polyalkylene oxide. In anotherpreferred embodiment, at least 1% of the —N(R^(3a))—R³—N(R^(3a))— groupsare independently selected from polyalkylene amine,

wherein R_(C) is a C₁₋₃alkyl group.

In another aspect, the invention provides an article that includes aflammable solvent with a flash point ranging from about −15° C. to about300° C. and an ester-terminated polyamide of formula (1) as definedabove. This article may further contain a wick. The flash point of thesolvent may range from about 40° C. to about 90° C. There is preferablya coating on at least a portion of the article's surface, where apreferred coating material is a dimer acid-based polyamide.

The invention also provides a flammable article which includesester-terminated dimer acid-based polyamide (ETDABP) and solvent, thesolvent having a flash point ranging from about −15° C. to about 300° C.and the ester-terminated dimer acid-derived polyamide being prepared bya method comprising reaction x equivalents of carboxylic acid fromdiacid or a reactive equivalent thereof, y equivalents of amine fromdiamine and z equivalents of hydroxyl from monoalcohol or a reactiveequivalent thereof, wherein at least about 10% of the carboxylic acidequivalents are from polymerized fatty acid, and monoalcohol issubstantially the only monofunctional reactant used to form the gellant,wherein each of x, y and z is greater than 0. This article may furthercontain a wick. In a preferred embodiment, 0.9≦{x/(y−z)}≦1.1, and0.1≦{z/(y−z)}≦0.7. As in the article described previously, this articlemay further contain a solid coating on at least a portion of the surfacethereof, and/or may contain an optional component selected fromcolorant, fragrance, insect repellent, insecticide, or preservative suchas antioxidant and UV-inhibitor.

The invention also provides a composition for the delivery of an activeingredient, where the composition includes an ester-terminated dimeracid-based polyamide (ETDABP) and an active ingredient, and has theconsistency of a gel. A preferred ETDABP has the formula (1) above. Thecomposition may be present within a container, or it may befree-standing as, for example, as stick. A preferred compositionincludes fragrance as the active ingredient, where suitable fragrancesare any of menthol, methyl salicylate and eucalyptus. Other suitableactive ingredients include insecticide, insect-repellent, sunscreen,bioactive ingredient, and colorant. The composition may have a solidpolymer coating present on at least a portion of the gel's surface. Apreferred composition is transparent.

The invention also provides a method of forming a coated article. Themethod includes the steps of providing a gel structure having anexterior surface, and then applying a coating to the exterior surface.The coating may be applied by any of (a) spraying the coating onto theexterior surface; (b) dipping the gel structure into asolvent-containing coating composition; or (c) dipping the gel structureinto a solvent-free molten coating composition.

These and related aspects of the invention are described further below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is graphical representation of the effect of temperature onrheology for a gelled hydrocarbon of the invention.

FIG. 2 shows the percent weight loss (based on the initial weight oflimonene) as a function of time for a gel of the invention and acomparative gel.

FIG. 3 shows the percent weight loss (based on the initial weight ofhexyl acetate) as a function of time for a gel of the invention and acomparative gel.

FIG. 4 shows the percent weight loss as a function of time for two gelsof the invention, which contain different volatile hydrocarboncomponents.

FIG. 5 illustrates a testing protocol for measuring the rigidity of asample.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a gelled composition that is stable,transparent and rigid. The composition is formed, at least in part, of agellant in combination with a solvent, where this combination forms thegel. The gellant is preferably ester-terminated dimer acid-basedpolyamide (ETDABP) and is more preferably ester-terminated polyamide(ETPA), where ETPA is a preferred ETDABP.

As used herein, ETDABP refers to those compositions which are formedupon reaction of dimer acid, diamine and monoalcohol. Before describingthe structure in detail, it is important to not that ETDABP may beformed from reactants other than dimer acid, diamine and monoalcohol,however, an ETDABP of the present invention will have the same, oressentially the same structural composition as is achieved by thereaction between dimer acid, diamine and monoalcohol. In other words, itis not necessary to use dimer acid, diamine and monoalcohol in formingan ETDABP of the present invention, however, ETDABP has the structurewhich would result upon reacting dimer acid, diamine and monoalcohol.For example, reactive equilavents of dimer acid, diamine and/ormonoalcohol could be reacted together to provide an ETDABP of theinvention.

Thus, reactive equivalents of diacids and/or diamines may be used in theinvention to form ETDABP. For example, diesters may be substituted forsome or all of the diacid, where “diesters” refers to the esterificationproduct of diacid with hydroxyl-containing molecules. However, suchdiesters are preferably prepared from relatively volatilehydroxyl-containing molecules, in order that the hydroxyl-containingmolecule may be easily removed from the reaction vessel subsequent tomonoalcohol and/or diamine (both as defined herein) reacting with thediester. A lower alkyl diester, e.g., the esterification ordiesterification product of diacid as defined herein and a C₁₋₄monohydric alcohol (e.g., methanol, ethanol, propanol and butanol), maybe used in place of some or all of the diacid in the ETDABPgellant-forming reaction of the invention. The acid halide of the diacidmay likewise be employed in place of some or all of the diacid, howeversuch a material is typically much more expensive and difficult to handlecompared to the diacid, and thus the diacid is preferred. Likewise, themonoalcohol may be esterified with a volatile acid, e.g., acetic acid,prior to being employed in the ETDABP gellant-forming reaction of theinvention. While such reactive equivalents may be employed in thereaction, their presence is not preferred because such equivalentsintroduce desired reactive groups into the reaction vessel.

The preferred reactants used to form ETDABP will now be described.

Dimer acid (also known as polymerized fatty acid) is a well knownmaterial of commerce, and thus need not be described in great detail.Polymerized fatty acid is typically formed by heating long-chainunsaturated fatty acids, e.g., C₁₈ monocarboxylic acids, to about200-250° C. in the presence of a clay catalyst in order that the fattyacids polymerize. The polymerization product typically comprises dimeracid, i.e., C₃₆ dicarboxylic acid formed by dimerization of the fattyacid, and trimer acid, i.e., C₅₄ tricarboxylic acid formed bytrimerization of the fatty acid. Polymerized fatty acid is typically amixture of structures, where individual dimer acids may be saturated,unsaturated, cyclic, acyclic, etc. A more detailed discussion of fattyacid polymerization may be found in, e.g., U.S. Pat. No. 3,157,681 andNaval Stores—Production, Chemistry and Utilization, D. F. Zinkel and J.Russell (eds.), Pulp Chem. Assoc. Inc., 1989, Chapter 23.

Because fatty acid polymerization typically forms much more dimer acidthan trimer acid, those skilled in the art sometimes refer topolymerized fatty acid as dimer acid, even though some trimer acid, andeven higher polymerization products, may be present in admixture withthe dimer acid. For preparing an ETDABP, it is preferred that thepolymerized fatty acid contain less than about 10 weight percent oftrimer acid, based on the total weight of the polymerized fatty acid,and that dimer acid constitute at least about 90 weight percent of thepolymerized fatty acid. More preferably, the dimer acid constitutesessentially all of the polymerized fatty acid.

Typical unsaturated fatty acids used to form polymerized fatty acidinclude oleic acid, linoleic acid, linolenic acid, etc. Tall oil fattyacid, which is a mixture containing long-chain unsaturated fatty acidsobtained as a byproduct of the wood pulping process, is preferred forpreparing polymerized fatty acid useful for preparing ETDABPs. Whiletall oil fatty acid is a preferred source of long-chain fatty acid, thepolymerized fatty acid may alternatively be prepared by polymerizationof unsaturated fatty acids from other sources, e.g., soybeans or canola.The polymerized fatty acid useful in forming ETDABP is a liquid, with anacid number on the order of about 180 to about 200.

The polymerization fatty acid may be hydrogenated prior to being used inthe ETDABP-forming reaction. Hydrogenation tends to provide for aslightly higher melting point for the inventive gellant, as well asprovide the gellant with greater oxidative and color stability.Hydrogenated polymerized fatty acid also tends to provide for a lightercolored ETDABP, and is a preferred polymerized fatty acid for use in thepractice of the present invention. Polymerized fatty acid, dimer acid,and hydrogenated versions thereof may be obtained from a number ofcommercial suppliers. For example, Union Camp Corporation (Wayne, N.J.)sells polymerized fatty acid under their UNIDYME® trademark.

The diamine reactant has two amine groups, both of which are preferablyprimary amines, and may be represented by the formulaHN(R^(3a))—R³—N(R^(3a))H. R^(3a) is preferably hydrogen, but may also bean alkyl group or may also join together with R³ or another R^(3a) toform a heterocyclic structure. Diamines wherein R^(3a) is not hydrogen,and/or wherein R³ is not a hydrocarbon, are referred to herein asco-diamines. When present, co-diamines are preferably used in a minoramount compared to the diamines. R³ may be a hydrocarbon group having atleast two carbon atoms, where the carbon atoms may be arranged in alinear, branched or cyclic fashion, and the group may be saturated orcontain unsaturation. Thus, R³ may be aliphatic or aromatic. PreferredR³ hydrocarbon groups have 2 to 36 carbon atoms, more preferred R³hydrocarbon groups have 2 to 12 carbon atoms, and still more preferredR³ hydrocarbon groups have 2 to 6 carbon atoms.

Exemplary diamines having hydrocarbon R³ groups, which are commerciallyavailable and may be used in the present invention include, withoutlimitation, ethylenediiamine (EDA), 1,2-diaminopropane,1,3-diaminopropane, 1,4-diaminobutane, 1,2-diamino-2-methylpropane,1,3-diaminopentane, 1,5-diaminopentane, 2,2-dimethyl-1,3-propanediamine,1,6-hexanediamine (also known as hexamethylenediamine, HMDA),2-methyl-1,5-pentanediamine, 1,7-diaminoheptane, 1,8-diaminooctane,2,5-dimethyl-2,5-hexanediamine, 1,9-diaminonane, 1,10-diaminodecane,1,12-diaminododecane, diaminophenanthrene (all isomers, including 9,10),4,4′-methylenebis(cyclohexylamine), 2,7-diaminofluorene, phenylenediamine (1,2; 1,3 and/or 1,4 isomers), adamantane diamine,2,4,6-trimethyl-1,3-phenylenediamine, 1,3-cyclohexanbis(methylamine),1,8-diamino-p-menthane, 2,3,5,6-tetramethyl-1,4-phenylenediamine,diaminonaphthalene (all isomers, including 1,5; 1,8; and 2,3) and4-amino-2,2,6,6-tetramethylpiperidine.

Suitable aromatic diamines (by which is meant molecules having tworeactive, preferably primary amine groups (—NH₂) and at least onearomatic ring (“Ar”)) include xylene diamine and naphthalene diamine(all isomers).

The R³ group of the diamine may contain oxygen atoms in the form of apolyalkylene oxide group, in which case the diamine may be referred toas a co-diamine. Exemplary polyalkylene oxide-based co-diamines include,without limitation, the JEFFAMINE™ diamines, i.e.,poly(alkyleneoxy)diamines from Huntsman Chemical, Inc. (Houston, Tex.),also known as polyether diamines. Preferred polyalkyleneoxide-containing co-diamines are the JEFFAMINE™ ED and D seriesdiamines. Ether-containing R³ groups are not preferred, as they tend tolower the melting point of the gellant to an undesirable extent.However, a mixture formed from small amounts of a polyalkyleneoxide-based diamine with a major amount of a hydrocarbon-based diamineis well-suited for use in the invention. In general, the diaminereactant may be a pure diamine as described above, or a mixture of suchdiamines.

The R³ group of the diamine may contain nitrogen atoms, where thesenitrogen atoms are preferably secondary or tertiary nitrogen atoms. Atypical nitrogen atom-containing R³ group having secondary nitrogenatoms is a polyalkylene amine, i.e., a group containing alternatingalkylene groups and amine groups (i.e., —NH— groups). The alkylene groupis preferably ethylene, i.e., —CH₂CH₂—, and the polyalkylene amine maybe presented by the formula NH₂—(CH₂CH₂NH)_(m)CH₂CH₂—NH₂ wherein m is aninteger from 1 to about 5. Diethylenetriamine (DETA) andtriethylenetetraamine (TETA) are representative examples. When thediamine contains two primary amines in addition to secondary amines, theETDABP-forming reaction is preferably conducted at relatively lowtemperature, so that the primary amines (in preference to the secondaryamines) react with the diacid component.

However, the nitrogen atoms in the nitrogen-containing R³ group may alsobe present as tertiary nitrogen atoms, e.g., they may be present in aheterocycle of

wherein R_(C) is a C₁₋₃ alkyl group. Bis(aminoethyl)-N,N′-piperazine andbis(aminopropyl)-N,N′-piperazine may be used to introduce these R³groups into an ETDABP, and these are exemplary co-diamines according tothe invention. In addition, the co-diamine may have one primary aminegroup and one secondary amine group (e.g., N-ethylethylenediamine or1-(2-aminoethyl)piperazine). Generally, it is preferred that aminecompounds having secondary amines not be present in the reaction mixtureto any great extent, because their incorporation into anester-terminated dimer acid-based polyamide tends to provide for poorergelling ability of the ETDABP.

In general, the diamine reactant may have the formulaHN(R^(3a))—R³—N(R^(3a))H wherein R^(3a) is preferably hydrogen, but mayalso be C₁₋₁₀alkyl, preferably C₁₋₅alkyl, and more preferably C₁₋₃alkyl.In addition, R^(3a) may join together with R³ or another R^(3a) group toform a heterocyclic structure. For example, when piperazine is used as aco-diamine, the two R^(3a) groups in the HN(R^(3a))—R³—NH(R^(3a))structure have joined together to form an ethylene bridge.

The monoalcohol may be represented by the formula R¹—OH, wherein R¹ is ahydrocarbon group, preferably but not necessarily having at least fourcarbon atoms. Thus, the monoalcohol can also be described as amonohydric alcohol. R¹ is preferably a C₁₋₃₆ hydrocarbon, morepreferably a C₁₂₋₂₄ hydrocarbon, still more preferably is a C₁₆₋₂₂hydrocarbon, and yet still more preferably is a C₁₈ hydrocarbon. As usedherein, the term C₁₋₃₆ refers to a hydrocarbon group having at least 1,but not more than 36 carbon atoms, and similar terms have an analogousmeaning. The carbon atoms of the hydrocarbon group may be arranged in alinear, branched or cyclic fashion, and the group may be saturated orunsaturated. However, R¹ is preferably linear, with the hydroxyl grouplocated on a terminal carbon atom, i.e., the monoalcohol is a primarymonoalcohol. Thus, 1-dodecanol, 1-tetradecanol, 1-hexadecanol (cetylalcohol), 1-octadecanol (steary alcohol), 1-eicosanol (arachidylalcohol) and 1-docosanol (behenyl alcohol) are preferred monoalcoholsfor preparing and ETDABP, where names in parentheses are common ortrivial names by which these monoalcohols are known. While themonoalcohol has been exemplified with saturated alkyl groups, themonoalcohol may alternatively contain an alkenyl group, i.e., an alkylgroup having unsaturation between at least two adjacent carbon atoms.One or a mixture of these alcohols may be used to prepare an ETDABPgellant.

Another monoalcohol reactant suited for the invention is a so-calledGuerbet alcohol. Guerbet alcohols have the general formulaH—C(Ra)(Rb)—CH₂—OH wherein Ra and Rb may be the same or different andpreferably represent a C₆₋₁₂ hydrocarbon group. Further discussion ofGuerbet alcohols may be found in, e.g., “Dictionary For Auxiliaries ForPharmacy, Cosmetics and Related Fields,” H. P. Fielder, 3^(rd) Ed.,1989, EDITION Cantor Aulendorf. 2-Hexadecyloctadecanol, which has 24carbon atoms, is a preferred Guerbet alcohol for use in the presentinvention.

Because R¹ is a hydrocarbon, the monoalcohol is a monofunctionalreactant under the reaction conditions employed to prepare an ETDABP (asdiscussed later). Furthermore, under preferred reaction conditions,R¹—OH is the only monofunctional reactant used to form the ETDABP. Thus,a reactant mixture useful in preparing ETDABP preferably does notcontain monocarboxylic acid (i.e., an organic molecule containing asingle carboxylic acid group) and/or monoamine (i.e., an organicmolecule containing a single amine group).

However, optional reactants may be employed to prepare an ETDABP gellantof the invention. For example, diacid other than dimer acid (i.e.,co-diacid) may be employed. In general, the diacid component of theETDABP-forming reaction mixture may be represented by the formulaHOOC—R²—COOH, and may therefore be referred to as a dicarboxylic acid, adibasic acid or a dibasic carboxylic acid. In general, R² is ahydrocarbon group where the carbon atoms thereof may be arranged in alinear, branched or cyclic fashion, and the group be saturated orunsaturated. In one embodiment of the invention, the diacid isexclusively polymerized fatty acid, as discussed above.

In another embodiment of the invention, the diacid used to prepare theETDABP gellant is a mixture of polymerized fatty acid and “co-diacid,”where the term co-diacid simply refers to any diacid of formulaHOOC—R²—COOH (where R² is defined above) excluding polymerized fattyacid. An exemplary co-diacid is a so-called “linear” diacid of theformula HOOC—R²—COOH wherein R² is a linear C₄₋₁₂ hydrocarbon group, andmore preferably is a linear C₆₋₈ hydrocarbon group. Linear diacidssuitable for the present invention include 1,6-hexanedioic acid (adipicacid), 1,7-heptanedioic acid (pimelic acid), 1,8-octanedioic acid(suberic acid), 1,9-nonanedioic acid (azelaic acid), 1,10-decanedioicacid (sebacic acid), 1,11-undecanedoic acid, 1,12-dodecanedioic acid(1,10-decanedicarboxylic acid), 1,13-tridecanedioic acid (brassylicacid) and 1,14-tetradecanedioic acid (1,12-dodecanedicarboxylic acid).

Another exemplary co-diacid that may be used to prepare an ETDABPgellant is the reaction product of acrylic or methacrylic acid (or theester thereof, with a subsequent hydrolysis step to form the acid) andan unsaturated fatty acid. For example, a C₂₁ diacid of this type may beformed by reacting acrylic acid with a C₁₈ unsaturated fatty acid (e.g.,oleic acid), where an ene-reaction presumably occurs between thereactants. An exemplary C₂₁ diacid is commercially available fromWestvaco Corporation, Chemical Division, Charleston Heights, S.C., astheir product number 1550.

Aromatic diacids may be used as the co-diacid. An “aromatic diacid” asused herein is a molecule having two carboxylic acid groups (—COOH) orreactive equivalents thereof (e.g., acid chloride (—COCl) or ester(—COOR)) and at least one aromatic ring (“Ar”). Phthalic acids, e.g.,isophthalic acid and terephthalic acid, are exemplary aromatic diacids.The aromatic diacid may contain aliphatic carbons bonded to the aromaticring(s), as in HOOC—C₂—Ar—CH₂—COOH and the like. The aromatic diacid maycontain two aromatic rings, which may be joined together through one ormore carbon bonds, (e.g., biphenyl with carboxylic acid substitution) orwhich may be fused (e.g., naphthalene with carboxylic acidsubstitution).

However, ETDABP gellants may also contain R² groups having less than 30carbon atoms. For example, an ETDABP gellant of the invention maycontain one or more R² groups having about 4 to 19, preferably about 4to 12, and more preferably about 4 to 8 carbon atoms. The carbon atomsmay be arranged in a linear, branched or cyclic fashion, andunsaturation may be present between any two carbon atoms. Thus, R² maybe aliphatic or aromatic. When present, these lower carbon-number R²groups are preferably formed entirely of carbon and hydrogen, i.e., arehydrocarbon groups. Such lower carbon-number R² groups preferablyconstitute less than 50% of the R₂ groups; however, when present,constitute about 1% to about 50%, and preferably about 5% to about 35%of the total of the R² groups. The identity of R² at each occurrence isindependent of the identity of R² at any other occurrence.

A preferred gellant of the invention, which is also a preferred ETDABPof the invention, is referred to herein as an ester-terminatedpolyamide, or ETPA. ETPA comprises molecules of the formula (1), whereinn, R¹, R² and R³ are defined herein.

Thus, the invention is directed to gels formed, in part, of anester-terminated polyamide of the formula (1) wherein n designates anumber of repeating units such that ester groups constitute from 10% to50% of the total of the ester and amide groups; R¹ at each occurrence isindependently selected from an alkyl or alkenyl group containing atleast 1 carbon atom, preferably at least 4 carbon atoms; R² at eachoccurrence is independently selected from a C₁₋₁₂ hydrocarbon group withthe proviso that at least 50% of the R² groups have 30-42 carbon atoms;R³ at each occurrence is independently selected from an organic groupcontaining at least two carbon atoms in addition to hydrogen atoms, andoptionally containing one or more oxygen and nitrogen atoms; and R^(3a)at each occurrence is independently selected from hydrogen, C₁₋₁₀ alkyland a direct bond to R³ or another R^(3a) such that the N atom to whichR³ and R^(3a) are both bonded is part of a heterocyclic structuredefined in part by R^(3a)—N—R³, such that at least 50% of the R^(3a)groups are hydrogen. For convenience, R¹, R², R³ etc. will be referredto herein as “groups”, however they could equally well be referred to asradicals (R¹) and diradicals (R² and R³).

As may be seen from formula (1), the preferred ETPA gellants have estergroups, i.e., —C(═O)O— groups (which may equally well be written as—OC(═O)— groups) at both ends of a series of amide groups, i.e.,—N(R^(3a))C(═O)— groups (which may equally well be written as—C(═O)N(R^(3a))— groups). The letter “n” designates the number ofrepeating units present in a molecule of ETPA, and is an integer greaterthan 0. According to the invention, n may be 1, in which case the ETPAcontains equal numbers of ester and amide groups, i.e., the ester groupsconstitute 50% of the total of the ester and amide groups in the ETPAmolecule. The preferred ETPA gellants are of relatively low molecularweight, so that n is preferably 1 to about 10, and more preferably is 1to about 5. Because the ETPA molecules have such a low molecular weight,they could equally well be referred to as ester-terminated oligoamides.In any event, viewed another way, the ester groups constitute about 10%to about 50%, preferably about 15% to about 40%, and more preferablyabout 20% to about 35% of the total of the ester and amide groups. Apreferred ETPA gellant includes a mixture of ETPA molecules of formula(1) having various n values.

The R¹ group in formula (1) is an alkyl or alkenyl group which containsat least 1, and preferably at least 4 carbon atoms. Alkyl groups arepreferred, however alkenyl groups having 1-3, and preferably 1 site ofunsaturation are also suitable. When ETPA molecules are made wherein R¹has 4 or less carbon atoms, the ETPA is a very poor gellant for purehydrocarbon, particularly pure aliphatic hydrocarbon. Accordingly, ETPAgellants having formula (1) wherein R¹ is less than four are preferablyused in preparing gels that are contained within a jar, rather thanfree-standing. Alternatively, the ETPA of formula (1) wherein R¹ is lessthan four might be used in combination with a gellant that provides amore rigid structure.

However, it has been surprisingly found that when the number of carbonatoms in the R¹ group is increased above 4, and preferably has at leastabout 10 carbon atoms, more preferably at least about 12 carbon atoms,then ETPA is an excellent gellant for aliphatic hydrocarbon. The upperrange for the number of carbon atoms in the R¹ group is not particularlycritical, however preferably the R¹ group has less than or equal toabout 24 carbon atoms, and more preferably has less than or equal to 22carbon atoms. R¹ groups having about 16-22 carbon atoms are highlypreferred. The identity of R¹ at any occurrence is independent of theidentity of R¹ at any other occurrence.

The R² group in formula (1) is suitably a hydrocarbon containing 4 to 42carbon atoms. A preferred R² group contains 30-42 carbon atoms (i.e., isa C₃₀₋₄₂ group), and at least 50% of the R² groups in an ETPA gellantpreferably have 30-42 carbon atoms. Such R² groups are readilyintroduced into an ETPA when the gellant is prepared from polymerizedfatty acid, also known as dimer acid. Polymerized fatty acid istypically a mixture of structures, where individual dimer acids may besaturated, unsaturated, cyclic, acyclic, etc. Thus, a detailedcharacterization of the structure of the R² groups is not readilyavailable. However, good discussions of fatty acid polymerization may befound in, e.g., U.S. Pat. No. 3,157,681 and Naval Stores—Production.Chemistry and Utilization, D. F. Zinkel and J. Russel (eds.), Pulp.Chem. Assoc. Inc., 1989, Chapter 23.

Typical unsaturated fatty acids used to form polymerized fatty acidinclude oleic acid, linoleic acid, linolenic acid, etc. Tall oil fattyacid, which is a mixture containing long-chain unsaturated fatty acidsobtained as a byproduct of the wood pulping process, is preferred forpreparing polymerized fatty acid useful in ETPA formation. While talloil fatty acid is a preferred source of long-chain fatty acid, thepolymerized fatty acid may alternatively be prepared by polymerizationof unsaturated fatty acids from other sources, e.g., soybeans or canola.The R² group containing 30-42 carbon atoms may thus be described ashaving the structure of dimer or trimer acid, after removal of thecarboxylic acid groups (as seen below, the carboxylic acid groups ofdimer acid can react to form the amide and/or ester groups of the ETPAgellant).

While the preferred ETPA gellants contain at least 50% C₃₀₋₄₂ groups asthe R² group, more preferably the total of the R² groups consist of atleast 75% C₃₀₋₄₂ groups, and still more preferably consist of at least90% C₃₀₋₄₂ groups. ETPA gellants of formula (1) wherein R² is entirelyC₃₀₋₄₂ are preferred gellants of the invention.

However, ETPA gellants may also contain R² groups having less than 30carbon atoms. For example, an ETPA gellant may contain one or more R²groups having about 4 to 19, preferably about 4 to 12, and morepreferably about 4 to 8 carbon atoms. The carbon atoms may be arrangedin a linear, branched or cyclic fashion, and unsaturation may be presentbetween any two carbon atoms. Thus, R² may be aliphatic or aromatic.When present, these lower carbon-number R² groups are preferably formedentirely of carbon and hydrogen, i.e., are hydrocarbon groups. Suchlower carbon-number R² groups preferably constitute less than 50% of theR₂ groups; however, when present, constitute about 1% to about 50%, andpreferably about 5% to about 35% of the total of the R² groups. Theidentity of R² at each occurrence is independent of the identity of R²at any other occurrence.

The —N(R^(3a))—R³—N(R^(3a))— group in formula (1) links two carbonyl(C═O) groups. In a preferred embodiment of the invention, all of theR^(3a) groups in an ETPA gellant are hydrogen, so that R³ alone joinsthe two nitrogen atoms shown in the formula —N(R^(3a))—R³—N(R^(3a))—. Inthis case, the R³ group contains at least two carbon atoms, andoptionally oxygen and/or nitrogen atoms, in addition to any hydrogenatoms that are necessary to complete otherwise unfilled valencies of thecarbon, oxygen and nitrogen atoms. In a preferred embodiment, R³ is ahydrocarbon group, having 2 to about 36 carbon atoms, preferably having2 to about 12 carbon atoms, and more preferably having 2 to about 8carbon atoms. These carbon atoms may be arranged in a linear, branchedor cyclic fashion, and unsaturation may be present between any two ofthe carbon atoms. Thus, R³ may contain aliphatic or aromatic structures.The identities of R³ and R^(3a) at each occurrence are independent oftheir identities at any other occurrence.

The R³ groups may contain oxygen and/or nitrogen in addition to carbonand hydrogen atoms. A typical oxygen atom-containing R³ group is apolyalkylene oxide, i.e., a group having alternating alkylene groups andoxygen atoms. Indeed, the oxygenation in a R³ group is preferablypresent as an ether group. Representative polyalkylene oxides include,without limitation, polyethylene oxide, polypropylene oxide andcopolymers (either random, alternating or block) of ethylene oxide andpropylene oxide. Such oxygenated R³ groups are readily introduced intoan ETPA molecule of the invention through use of Jeffamine™ diamines(Huntsman Chemical, Inc., Houston, Tex.). These materials are availablein a wide range of molecular weights. While some of the R³ groups maycontain oxygen (at least about 1%), preferably a minor number (less than50%) of the R³ groups contain oxygen, and more preferably less thanabout 20% of the R³ groups contain oxygen. The presence ofoxygen-containing R³ groups tends to lower the softening point of theETPA.

When present, the nitrogen atoms in an R³ group are preferably presentas secondary or tertiary amines. A typical nitrogen atom-containing R³group having secondary amine groups is a polyalkylene amine, i.e., agroup containing alternating alkylene groups and amine groups, which issometimes referred to as a polyalkylene polyamine. The alkylene group ispreferably a lower alkylene group, e.g., methylene, ethylene, (i.e.,—CH₂CH₂—), propylene etc. A typical polyalkylene amine may berepresented by the formula —NH—(CH₂CH₂NH)_(m)CH₂CH₂—NH— wherein m is aninteger from 1 to about 5.

However, the nitrogen atoms in the nitrogen-containing R³ group mayalternatively (or additionally) be present as tertiary nitrogen atoms,e.g., they may be present in a heterocycle of the formula:

wherein R_(c) is a C₁₋₃ alkyl group.

In the above-described nitrogen atom-containing R³ groups, R^(3a) washydrogen. However, R^(3a) is not limited to hydrogen. In fact, R^(3a)may be a C₁₋₁₀alkyl group, preferably a C₁₋₅alkyl group, and morepreferably a C₁₋₃alkyl group. In addition, R³ and R^(3a), or two R^(3a)groups, may together form a heterocyclic structure, e.g., a piperazinestructure such as

In this case, the two R^(3a) groups may be seen as joining together toform an ethylene bridge between the two nitrogen atoms, while R³ is alsoan ethylene bridge.

The ETPA gellant typically includes a mixture of ETPA molecules offormula (1) in addition to, for example, by-products that are formedduring the ETPA-forming reaction. While the ETPA molecules of formula(1) may be purified from such by-products using, e.g., chromatography ordistillation, the by-products are typically either minimal in amount orimpart desirable properties to the gellant, and thus need not beseparated from the molecules of formula (1) in order for a suitable ETPAgellant to be formed.

As described herein, alcohols, amines and carboxylic acids are preferredstarting materials to form the ETDABP and ETPA gellants of theinvention. These starting materials are preferably reacted together witha stoichiometry, and under reaction conditions, such that the acidnumber of the resulting gellant is less than 25, preferably less than15, and more preferably less than 10, while the amine number ispreferably less than 10, more preferably less than 5, and still morepreferably less than 1. The softening point of the gellant is preferablygreater than room temperature, more preferably is about 50° C. to about150° C., and still more preferably is about 80° C. to about 130° C.

In the ETDABP- and ETPA-gellant forming reactions of the invention, somematerial of formula (1) wherein n=0, i.e., diester, is typically beformed. Such a gellant could also be produced by preparing ETDABP asdescribed above (having little or no n=0 material), and then preparingdiester of formula (1) (n=0 exclusively, having no amide groups) in aseparate reaction, and mixing the two materials together. However,diester alone is not a useful gellant, and thus the ETDABP- andETPA-gellants preferably contain only small quantities of the diester,e.g., less than 10% by weight and more preferably even less.

It is important to control the stoichiometry of the reactants in orderto prepare an ETPA gellant according to the invention. In the followingdiscussion regarding reactant stoichiometry, the terms “equivalent(s)”and “equivalent percent” will be used, and are intended to have theirstandard meanings as employed in the art. However, for additionalclarity, it is noted that equivalents refer to the number of reactivegroups present in a molar quantity of a molecule, such that a mole of adicarboxylic acid (e.g., sebacic acid) has two equivalents of carboxylicacid, while a mole of monoalcohol has one equivalent of hydroxyl.Furthermore, it is emphasized that the diacid has only two reactivegroups (both carboxylic acids), the monoalcohol has only one reactivegroup (a hydroxyl group) and the diamine has only two reactive groups(preferably both primary amines), and these are preferably, although notnecessarily, the only reactive materials present in the reactionmixture.

In preparing an ETPA gellant, the equivalents of carboxylic acid aresubstantially equal to the combined equivalents of hydroxyl contributedby monoalcohol and amine contributed by diamine. In other words, if thereaction mixture used to form an ETPA gellant has “x” equivalents ofcarboxylic acid, “y” equivalents of amine and “z” equivalents ofhydroxyl, then 0.9≦{x/(y−z)}≦1.1, and preferably {x/(y−z)} issubstantially 1.0. Under these conditions, substantially all of thecarboxylic acid groups will react with substantially all of the hydroxyland amine groups, so that the final product contains very littleunreacted carboxylic acid, hydroxyl or amine groups. In other words,each of the acid and amine numbers of the gellant is preferably lessthan about 25, is more preferably less than about 15, and is still morepreferably less than about 10, and is yet still more preferably lessthan about 5.

When co-diacid is employed to prepare an ETPA gellant, the co-diacidpreferably contributes no more than about 50% of the equivalents ofcarboxylic acid present in the reaction mixture. Stated another way, theco-diacid contributes from 0-50 equivalent percent of the acidequivalents in the reaction mixture. Preferably, the co-diacidcontributes 0-30 equivalent percent, and more preferably contributes0-10 equivalent percent of the acid equivalents in the reaction mixture.

When co-diamine is employed to prepare an ETPA gellant, the co-diaminepreferably contributes no more than about 50% of the equivalents ofamine present in the reaction mixture. Stated another way, theco-diamine contributes from 0-50 equivalent percent of the amineequivalents in the reaction mixture. Preferably, the co-diaminecontributes 0-30 equivalent percent, and more preferably contributes0-10 equivalent percent of the amine equivalents in the reactionmixture.

In order to prepare the ETPA gellant, it is important to control therelative equivalents of hydroxyl and amine used in the gellant-formingreaction. Thus, hydroxyl groups contribute about 10-70% of the totalequivalents of hydroxyl and amine employed to prepare the gellant.Stated another way, 0.1≦{z/(y+z)}0.7, where y and z have been definedabove. In a preferred embodiment, 0.2≦{z/(y+z)}≦0.5, while in a furtherpreferred embodiment, 0.25≦{z/(y+z)}≦0.4.

The stoichiometry of the reactants will have a significant impact on thecomposition of the ETDABP and ETPA gellants. For example, ETDABP andETPA gellants made with increasing amounts of monoalcohol will tend tohave lower average molecular weights. In other words, as moremonofunctional reactant is used, the number of amide pairs in an averagemolecule of formula (1) will decrease. In fact, when 70 equivalentpercent monoalcohol is employed, the majority of the molecules offormula (1) in the gellant will have only one or two amide pairs. On theother hand, as less monoalcohol is used, the average molecular weight ofthe molecules in the ETDABP or ETPA gellant will increase. In general,increasing the average molecular weight of the ETDABP or ETPA componentswill tend to increase the melting point and melt viscosity of thegellant, which tends to provide a firmer gel when the gellant iscombined with a low polarity liquid or other solvent.

In order to prepare an ETDABP gellant, the above-described reactants(diacid, diamine and monoalcohol or reactive equivalents thereof) may becombined in any order. Preferably, the reactants are simply mixedtogether and heated for a time and at a temperature sufficient toachieve essentially complete reaction, to thereby form the ETDABPgellant. During formation of the ETDABP gellant, the diacid and diaminegroups will alternate to form what may be termed an alternatingcopolymer. Neither ETDABP nor ETPA is a block copolymer. The terms“complete reaction” and “reaction equilibrium” as used herein haveessentially the same meaning, which is that further heating of theproduct gellant does not result in any appreciable change in theperformance characteristics of the product gellant, where the mostrelevant performance characteristic is the ability of the productgellant to form a clear, firm gel upon being combined with a solvent.

Thus, the ETDABP gellant may be formed in a one-step procedure, whereinall of the monoalcohol, diacid (including co-diacid) and diamine(including co-diamine) are combined and then heated to about 200-250° C.for a few hours, typically 2-8 hours. Since one or more of the reactantsmay be a solid at room temperature, it may be convenient to combine eachof the ingredients at a slightly elevated temperature, and then form ahomogeneous mixture prior to heating the reaction mixture to atemperature sufficient to cause reaction between the monoalcohol, diacidand diamine. Alternatively, although less preferably, two of thereactants may be combined and reacted together, and then the thirdreactant is added followed by further heating until the desired productis obtained. Reaction progress may be conveniently monitored byperiodically measuring the acid and/or amine number of the productmixture.

As one example, the diacid may be reacted with the diamine so as to formpolyamide, and then this intermediate polyamide may be reacted withmonoalcohol to form ester-terminated dimer acid-based polyamide. Or, thediacid may be reacted with the monoalcohol to thereby form diester, andthis diester may be reacted with diamine to thereby formester-terminated dimer acid-based polyamide. Because the components ofthe product gellant are preferably in reaction equilibrium (due totransamidation and transesterification reactions), the order in whichthe reactants are combined preferably does not impact on the propertiesof the gellant.

Any catalyst that may accelerate amide formation between carboxylic acidand amine groups, and/or ester formation between carboxylic acid andhydroxyl groups, may be present in the reaction mixture described above.Thus, mineral acid such as phosphoric acid, or tin salts such asdibutyltin oxide, may be present during the reaction. In addition, it ispreferred to remove water from the reaction mixture as it is formed uponamide and ester formation. This is preferably accomplished bymaintaining a vacuum on the reacting mixture.

The gels of the invention are formed from components including at leastone each of a gellant and a solvent, where a preferred gellant is ETDABPas described above. The gels may be formulated to function as a candleor other article which will be intentionally burned, in which case thesolvent is preferably flammable. Whether or not the gel is flammable oris intended to be burned, it may contain various active ingredients. Theactive ingredient is a material which interacts with the environmentaround the active ingredient-containing gel. For instance, fragrance maybe an active ingredient of the gel. The fragrance may be the, or one ofthe solvents which forms a gel with ETDABP. In general, the solvent may,but need not, serve more than one purpose, i.e., in addition to forminga gel with the gellant, the solvent may have other properties whichallow it to be an active ingredient. Thus, the solvent is an importantcomponent of the gel, and will be described next. In general, thesolvent is preferably non-aqueous, in that it does not contain anyappreciable amount of water. This is true regardless of whether thearticle is intended to be flammable, e.g., a candle or fuel, or containsan active ingredients.

When a gel is formulated with the intention that the gel-containingarticle will be burned, the solvent is preferably flammable. Thus, thegel preferably does not contain appreciable moisture when the gel isintended to be a component in an article which should be burned. Aflammable solvent for preparing gels of the invention typically has aflash point ranging from about −15° C. to about 300° C., and preferablyfrom about −15° C. to about 225° C. When the article is primarilyintended to be a fuel source, i.e., is intended to be used to assist thelighting of a fire in a fireplace, a campfire, a charcoal fire, etc.,then the flash point of the solvent preferably ranges from about −15° C.(e.g., hexane) to about 225° C. (e.g., heavy mineral oil). A preferredflash point is between about 40° C. and about 90° C. When the article isprimarily intended to be a candle, i.e., primarily for decorativepurposes and home use, then the flash point of the solvent should beabout 130° C. to about 225° C., and is preferably about 150° C. to about200° C. Candles, more than fuel sources, are intended for slow burningand may be left unobserved for periods of time. For these reasons, ahigher flash point is generally preferred for a candle compared to afuel source, so that the candle burns more slowly and safely.

Methods to measure flash point are well known. For example, ASTM D-92and D-93 provide procedures for determining the flash point of asolvent. The current address for ASTM is 100 Barr Harbor Drive, WestConshohocken, Pa. 19428-2959. ASTM D92-90 (i.e., test D92, last revisedin 1990) as set forth in the Annual Book of ASTM Standards, Section 5(pages 28-32 in 1996 edition), is directed to a test method formeasuring flash and fire points by the so-called Cleveland Open Cupmethod. The Cleveland Open Cup method is particularly suited formeasuring the flash points of viscous materials having a flash point of79° C. and above, i.e., liquids with relatively high flash points suchas mineral oils. ASTM D93-94 as set forth in the Annual Book of ASTMStandards, Section 5 (pages 33-46 is 1996 edition), is directed to atest method for measuring flash-point by the Pensky-Martens Closed CupTester. The Pensky-Martens Closed Cup Tester may be used with fuel oils,lubricating oils, and other homogeneous liquids. VWR ScientificProducts, having a website at http://www.vwrrsp.com, presently sells aPensky-Martens Flash Point Tester. Electric Boekel; a Pensky-MartensFlash Point Tester. Precision: and a Tag Closed Cup Flash Tester,Koehler, any of which may be used to determine flash points according tothe present invention.

While flash point may be measured by the above-listed techniques, inaddition, many reference books and catalogs provide flash pointinformation about solvents and fuels. For example, the Aldrich ChemicalCompany (Milwaukee, Wis.) offers a catalog of over a thousand chemicals,and in this catalog the flash points of many of the available chemicalsis set forth. The Material Data Safety Sheet (MSDS) that is oftenavailable from a chemical manufacture, typically provides flash pointinformation about the chemical.

The solvent may be a liquid or solid at room temperature, but ispreferably a liquid. Examples of solvents that are solid at roomtemperature include fatty acids and fatty alcohols, such as myristicacid (flash point>159 C.) and myristyl alcohol (flash point>143° C.).The solvent is preferably a liquid at a temperature between 10-60° C.

A preferred solvent is a low polarity liquid, while a preferred lowpolarity liquid is a hydrocarbon, and preferred hydrocarbons are oils.As used herein, the term solvent includes any substance which is aliquid at a temperature between 10-60° C., and which forms a gel uponbeing combined with a gellant. The prior art sometimes distinguishessolvents and oils in that defatting occurs when solvents are rubbed onhuman skin, leading to drying and irritation, however, defatting doesnot occur when oils are rubbed on human skin. As used herein, the termsolvent will be used to encompass oils and other fluids which may begelled, and is not limited to liquids that cause defatting of humanskin.

Many different oils may be used as solvents in the present invention,including vegetable oil, animal oil and mineral oil. However a preferredoil is mineral oil, also sometimes referred to as medicinal oil. Mineraloil is a highly refined, colorless, tasteless, and odorless petroleumoil (i.e., derived by processing petroleum/crude oil) used medicinallyas an internal lubricant and for the manufacture of salves andointments. Such mineral oils are highly refined in having substantiallyall volatile hydrocarbons removed therefrom, and in being hydrogenated(also called hydrotreated) in order to remove substantially allunsaturation, e.g., aromatic groups have been reduced to the fullysaturated analog. A preferred mineral oil to prepare a gel of theinvention is so-called “white” mineral oil, which is water-white (i.e.,colorless and transparent) and is generally recognized as safe forcontact with human skin. Mineral oil may also be characterized in termsof its viscosity, where light mineral oil is relatively less viscousthan heavy mineral oil, and these terms are defined more specifically inthe U.S. Pharmacopoeia, 22^(nd) revision, p. 899 (1990).

Any mineral oil may be used in the invention as a solvent to form a gel.Mineral oils are available commercially in both USP and NF grades. USPmineral oils have viscosities that range from 35 cSt to 100 cSt, andpour points that range from −40° C. to −12° C. NF light mineral oilshave lower viscosities, typically 3-30 cSt, and pour points as low as−45° C. The mineral oil may be of technical grade, having a viscosityranging from 4-90 cSt and a pour point ranging from −12° C. to 2° C.

Examples of suitable, commercially available mineral oils includeSonneborn® and Carnation® white oils from Witco, Isopar® K and Isopar® Hfrom Exxon, and Drakeol® and Peneteck® white mineral oils from Penreco.

Other hydrocarbon solvents that may be used in the invention includerelatively lower molecular weight hydrocarbons including linearsaturated hydrocarbons such a tetradecane, hexadecane, octadecane, etc.Cyclic hydrocarbons such as decahydronaphthalene (DECALIN), fuel gradehydrocarbons, branched chain hydrocarbons such as PERMETHYL fromPermethyl Corporation and ISOPAR from Exxon Corp., and hydrocarbonmixtures such as product PD-23 from Witco (Greenwich, Conn.) may also beused in preparing gels of the invention. Such hydrocarbons, particularlysaturated hydrocarbon oils, are a preferred solvent for preparing a gelof the invention.

Another class of suitable low polarity liquid solvents is esters, andparticularly esters of fatty acids. Such esters may be monofunctionalesters (i.e., have a single ester moiety) or may be polyfunctional(i.e., have more than one ester group). Suitable esters include, but arenot limited to, the reaction products of C₁₋₂₄ monoalcohols with C₁₋₂₂monocarboxylic acids, where the carbon atoms may be arranged in alinear, branched and/or cyclic fashion, and unsaturation may optionallybe present between carbon atoms. Preferably, the ester has at leastabout 18 carbon atoms. Examples include, but are not limited to, fattyacid esters such as isopropyl isostearate, n-propyl myristate, isopropylmyristate, n-propyl palmitate, isopropyl palmitate, hexacosanylpalmitate, octacosanyl palmitate, triacontanyl palmitate, dotriacontanylpalmitate, tetratriacontanyl palmitate, hexacosanyl stearate,octacosanyl stearate, triacontanyl stearate, dotriacontanyl stearate andtetratriacontanyl stearate: salicylates, e.g., C₁₋₁₀ salicylates such asoctyl salicylate, and benzoate esters including C₁₂₋₁₅ alkyl benzoate,isostearyl benzoate and benzyl benzoate.

Suitable esters include glycerol and propylene glycol esters of fattyacids, including the so-called polyglycerol fatty acid esters andtriglycerides. Exemplary esters include, without limitation, propyleneglycol monolaurate, polyethylene glycol (400) monolaurate, castor oil,triglyceryl diisostearate and lauryl lactate. Thus, the solvent may havemore than one of ester, hydroxyl and ether functionality. For example,C₁₀₋₁₅ alkyl lactate may be used in forming a gel of the invention. Inaddition, esterified polyols such as the polymers and/or copolymers ofethylene oxide, propylene oxide and butylene oxide reacted with C₁₋₂₂monocarboxylic acids are useful. The carbon atoms of the C₁₋₂₂monocarboxylic acids may be arranged in a linear, branched and/or cyclicfashion, and unsaturation may be present between the carbon atoms.Preferred esters are the reaction product of an alcohol and a fattyacid, where the alcohol is selected from C₁₋₁₀ monohydric alcohol, C₂₋₁₀dihydric alcohol and C₃₋₁₀ trihydric alcohol, and the fatty acid isselected from a C₃₋₂₄ fatty acid. Two triglyceride esters that arecommercially available and may be used as a solvent in the presentinvention are Softigen® from Hüls America of Piscataway, N.J. (a C₁₀-C₁₈triglyceride), and Neobee® M5 from Stepan Chemical of Northfield, Ill.(a liquid capric/caprylic triglyceride).

In order to prepare a gel from ETDABP or ETPA and a solvent, the twocomponents are mixed together and heated until homogeneous. Atemperature within the range of about 80-150° C. is typically sufficientto allow the gellant to completely dissolve in the solvent. A lowertemperature may be used if a solution can be prepared at the lowertemperature. Upon cooling, the mixture forms the gel of the invention.

A precise definition of “gel” is not easy to give, although most if notall researchers recognize a “gel.” Generally, a gel is more viscous thana liquid or paste, and retains its shape when left undisturbed, i.e., isself-supporting. However, a gel is typically not as hard or firm as awax. Gels may be penetrated more easily than a wax-like solid, where“hard” gels are relatively more resistant to penetration than “soft”gels. A rigid gel as defined herein resists deformation upon theapplication of a force.

Almdale et al. (Polymer Gels and Networks, Vol. 1, No. 5 (1993)) listtwo criteria for defining a system as a gel: (1) a gel consists of twoor more components, one of which is a liquid, present in substantialquantities; and (2) a gel is a soft material which is solid orsolid-like. The solvents described herein include the liquid of Almdale.Whether Almdale's “soft material” is a gel can be described moreaccurately through theological measurement. Typically, gels possess astorage modulus G′(w) which exhibits a pronounced plateau at higherfrequencies (on the order of 1-100 radians/second), and a loss modulusG″(w) which is considerably smaller than the storage modulus in theplateau region. In a strict sense, the term “gel” applies to systemshaving a value G′(w) that is higher than its value of G″(w) at lowfrequencies. Many of the compositions according to the present inventionare gels by one or both of the above definitions. A gel is free-standingor self-supporting in that its yield value is greater than the shearstress imposed by gravity.

Rheological parameters such as the storage modulus G′(w) can be measuredas a function of angular frequency with a parallel-plate rheometer. Forexample, such parameters can be generated using a Rheometrics DynamicAnalyzer Model 70, using a 0.5 cm stainless steel plate and a 2.3 mmsample gap, over a temperature sweep of 25-85° C. at 1% strain and 6.3radians/sec. A characterization of the rheological behavior of a gelledbody according to the present invention was made using the Rheometricsinstrument and conditions set forth above. The gel was preparedaccording to Example 3 set forth herein. As demonstrated by FIG. 1, theelastic modulus (G′) is 5-10 fold greater than the loss modulus (G″) atroom temperature for this composition, thus demonstrating that a gelstructure is present. As the gel is heated, it retains significantgel-like character at least up to about 50° C. However, as the gel isfurther heated, and the melting point of the ETDABP gellant is reached,the loss modulus will eventually equal the storage modulus (i.e., tan δequals 1), and the composition loses its gel-like character (at atemperature of about 65-70° C., based on extrapolation of the data inFIG. 1).

Preferably, the solvent is a low-polarity liquid as described above, andmore preferably the solvent is a liquid hydrocarbon. A liquid solventmay contain more than one component, e.g., hydrocarbon as well asester-containing material. In the mixture, the gellant (e.g., ETDABP)contributes 10-95%, and the solvent contributes 5-90% of the combinedweight of the gellant and the solvent. Preferably, the gellant iscombined with the solvent such that the weight percent of gellant in thegellant—solvent mixture is about 5-50%, and preferably is about 10-45%.Such gels may be transparent, translucent or opaque, depending on theprecise identities of the gellant and solvent, as well as theconcentration of gellant in the mixture.

After the molten homogeneous mixture of gellant and solvent has beenformed, it is allowed to cool, whereupon it forms a gel. The gel may beused as a candle or fuel, however when it is intended that the gel beburned, the gel preferably does not contain an appreciable amount ofmoisture, i.e., the gel is preferably non-aqueous. Thus, solvents of thepresent invention are preferably substantially moisture-free, i.e., arenon-aqueous.

A gel formed from ETDABP or ETPA may adhere to the sides of thecontainer in which the gel is formed. During cooling, the moltenhomogeneous mixture will undergo some contraction, which may be impededif the gel sticks to the sidewalls of the container. In these instances,cracks may form in the cooling gel, because the contracting gel isadhering to the container. When a crack-free candle or other article isdesired, such a product may be prepared by allowing the gel to cool tojust above its gel point, and then pouring the cooled gel into a mold.In this way, the degree of cooling, and hence contraction, that occurswithin the mold is minimized, with concomitant reduction in cracking.

If desired, the molten mixture may be poured into a mold or a jar, andthe mixture-cooled therein to form the candle or fuel. A mold may beused when the gel desirably has an ornamental exterior surface. Forexample, the mold may impart various designs, in a relief fashion, tothe surface of the gel. A preferred relief design is a ridged pattern,with the ridges preferably extending vertically (from top to bottom)along the sides of the candle. These ridges are desirable because theyminimize the surface area which is contacted when a person picks up thecandle, and therefore there is less opportunity for smudges andfingerprints to be imparted to the surface of the candle.

Molds to achieve various relief surfaces are commonly used in thepreparation of paraffin-based candles, and are well known in the art. Apillar shape, which is a common and desired form for candles, is apreferred shape for the gel. Cubes and cylinders are other suitableshapes for the gel. An appropriate quantity of mold-release agent may beplaced on the interior mold surface, in order to facilitate removal ofthe gel from the mold. Such mold-release agents may contain silicon orfluorocarbon, are available from many commercial sources, and are knownin the art.

Alternatively, the molten mixture may be poured into a jar or likecontainer, to permanently hold the gel. The jar may be formed of clearor colored glass, and have essentially any shape, according to theaesthetic preferences of the manufacturer. Alternatively, the jar may beformed of any other non-inflammable substance, e.g., metal. A noteworthyfeature of the ETDABP gels of the invention is their transparent andcolorless appearance, and thus containers which allow the consumer toappreciate this appearance, e.g., clear glass or mirrored surface jars,are preferred. However, when the gel will be used primarily as a fuelsource during, for example, camping, the container is preferably robustand not easily broken. For these instances, the container is preferablymetal, e.g., aluminum or the like. Essentially the same procedures andconsiderations are relevant when preparing a non-flammable gel of theinvention, which is intended primarily as a carrier for one or moreactive ingredients.

Regardless of whether the molten mixture is cooled in a mold or a jar,various decorative items may be placed within the mixture to enhance theappearance thereof. Such decorative items include so-called botanicals,which manufacturers currently place just below the surface of a paraffincandle, in order that the shadow of a leaf or otherwise shaped articlecan be seen on the candle's surface. Because the candles of the presentinvention may be transparent, such botanicals may be placed anywherewithin the candle, to provide for a pleasing appearance. As anotherexample, colored paraffin beads, or otherwise shaped items, may be addedto the molten mixture at an appropriate time during its cooling, so thatthe decorative items are suspended in the gel. As yet another example,colorant may be gently stirred into the otherwise clear and coolingmolten mixture, so that coloration in a swirling pattern may be seen inthe final gel. The botanicals, bead or other decorative items should beadded to the cooling molten mixture at a time when the viscosity of themolten mixture is such that the decorative items will not simply sink tothe bottom of the mold or jar. This time will depend on the exactidentity of the decorative items, and can be readily determined by theskilled artisan without undue experimentation.

When a wick is positioned in a flammable gel as described herein, acandle is formed. Such a candle has a surface which is preferably freeof bubbles, cracks, chips, etc., when seen by the unaided eye. Thecandle may be transparent, translucent or opaque, and may be colorless,white or any other color, if dyes or pigments are added to theformulation. The candle preferably contains a single wick, where thewick is preferably positioned in the center of the candle.Alternatively, the candle may have a plurality of wicks. Upon burning,the candle preferably displays a bright, calm, flame, and graduallyforms a pool surrounding the so-called cup rim.

Candle wicks are commercially available, and the precise wick should beselected, in part, based on the size of the candle. A preferred wick ismade from uniform, tear-resistant cotton yarn made of medium- andlong-stapled cotton which is seasoned and does not have moisture damage.A typical wick has from 15-42 strands (plys). A larger wick (morestrands) is preferred for a larger candle. A transparent wick may beused, so that the entire candle (wick plus fuel, and coating if present)may be transparent. The wick should be free of contaminants which impaira suction effect needed for desirable burning. The wick should not leaveashes upon burning, and it should burn without visible release of soot.A preferred wick has an upright posture upon exiting the candle, with aslight curvature and formation of a glow point at the wick tip uponburning. The wick in a preferred candle has a medium curvature while thecandle burns, and the flame burns without visible release of soot. Thereis preferably a slight afterglow formed immediately after the candle hasbeen extinguished.

The wick may be embedded with wax or other additive which facilitates orprovides desired burning properties. For example, the wick may becolored using a water or alcohol soluble dye. Examples of water andalcohol soluble dyes that may be used to color the wick include, withoutlimitation, F,D&C Blue #1, D&C Orange #4, Ext D&C Violet #2, F,D&C Red#4, D&C Red #33, F,D&C Red #40, D&C Green #8, D&C Yellow #10, F,D&CYellow #5 and D&C Green #5.

When the gelled body is to be used primarily as a fuel source, e.g., tomaintain heat in a warmed tray of food, or to start a campfire, etc.,the gelled body does not necessarily contain a wick. In general, theconcentration of ETDABP can be 1-95 wt. % of the total weight of thegelled body. A preferred composition is 1-20 wt. % ETPA, 80-99 wt. %mineral oil (preferably with a flash point of 100-200° C.) and 0-10 wt.% fragrance, where the wt. % values are based on the total weight of thegelled body. As stated above, ISOPAR K and ISOPAR H (Exxon Chemicals,Houston, are preferred solvents for the gelled article intended as aheat source.

When preparing a candle or fuel, other optional ingredients, such ascolorant, fragrance, insect repellant, insecticide, and/or preservative(for example, antioxidant and/or UV-inhibitor), may be added at any timeprior to formation of the gel structure. For example, they may be addedafter the gellant and solvent have formed a homogeneous mixture.Alternatively, they may be added prior to the formation of a homogeneousmixture.

The preservative, which may be an antioxidant and/or a UV-inhibitor,should be present in an amount effective to achieve its or their desiredpurposes. Typically, at least about 0.1 wt. % of one or both of anantioxidant and UV-inhibitor will be present in an article of theinvention. Suitable antioxidants and UV-inhibitors are well known in theart and include, without limitation, hydroxyditoluene, stearichydrazide, 2,6-di-tert-butyl-4-methylphenol (BHT, an antioxidant),Irganox® 1010 hindered phenol antioxidant from Ciba-Geigy (Hawthorne,N.Y.) and Uvinul® 3206 UV-inhibitor from BASF, Parsipany, N.J..

The colorant may, for example, be a pigment or a dye, however a dye ispreferred for providing transparent articles. Dyes that are oil solubleare particularly well suited. Oil soluble dyes are well known in theart, and may be obtained from, for example, Pylam Products, Tempe Ariz..Pylam Products sells the following oil soluble dyes: D&C violet #2, D&Cyellow #11, D&C green #6, D&C red #17, Pylakrome™ Red, Pylakrome™brilliant blue, Pyla-Wax™ brilliant blue, Pyla-Wax™ canary yellow,Pyla-Wax™ violet A, and Pyla-Wax™ brilliant red, among others.

The amount of dye which should be present in the gel will depend on theintensity of the dye and the desired strength of the coloration of thegel. This amount can be readily determined by the skilled artisan, withlittle or no experimentation. Typically, a colorant amount of less than1 wt. % (based on the total weight of the gel) is satisfactory, andoften an amount of less than 0.5 wt. % or less than 0.25 wt. % issatisfactory. The colorant may be mixed together with the solvent andgellant at any time prior to, or during, formation of the gel.

Another optional ingredient is a fragrance. The term “fragrance” isintended to refer to a chemical or blend of chemical raw materials thattogether have a desirable odor. Fragrances, therefore, typically consistof a blend of chemicals, fragrant chemicals or fragrance materials. Alarge number of fragrance materials are known and used in variousproducts such as perfumes, cosmetics, soaps, detergents, etc. Any of thefragrance materials used in these products may be added to a gel of thepresent invention. Bush Boake Allen of Montvale, N.J. sells a largenumber of fragrance raw materials, some of which have been evaluated foruse in gels of the present invention as set forth in Example 35 herein.The vast majority of the fragrance materials disclosed in Example 35 arethemselves solvents, and have a flash point between −15° C. and −300° C.Furthermore, most if not all of these fragrance materials of Example 35are compatible with the gels of the invention. These fragrance rawmaterials may be combined in numerous ways to create pleasing fragrancesfor candles and other compositions disclosed herein.

The amount of fragrance which should be present in the gel will dependon the intensity of the fragrance and the degree to which it is desiredthat the gel emit fragrance. This amount can be readily determined bythe skilled artisan, with little or no experimentation. An amount offragrance equal to at least about 0.1 wt. % based on the total weight ofthe composition, is typically necessary in order to achieve at leastsome fragrance-emitting character for the composition. Typically, afragrance amount of less than 50 wt. % (based on the total weight of thegelled body) is satisfactory, and often an amount of less than 20 wt. %or even less than 15 wt. % is satisfactory. In a typical gel havingfragrance, the fragrance constitutes 1-5 wt. % of the total weight ofthe gel. The amount of fragrance in a candle may depend upon thepresence of other optional ingredients. For example, when insectrepellent is present in the candle, the fragrance concentration istypically less than 30 wt. % of the total weight of the gel, andpreferably is 1-5 wt. %.

The fragrance may be mixed together with the solvent and gellant at anytime prior to formation of the gel. However since many fragrancematerials are rather volatile, it is preferred to add the fragrance tothe ungelled composition at a relatively low temperature rather than ahigher temperature. A temperature of about 80° C. is typically suitablefor adding the fragrance to the gel.

Another optional ingredient is an insect repellant. Suitable insectrepellants include, without limitation, citronella, DEET, terpineol, andbenzalacetone. In a typical gel, the insect repellent constitutes about0.1-20 wt. %, preferably 5-10 wt. % of the total weight of the gel. Whena candle contains insect repellant, the preferred gellant concentrationis 30-60 wt. % when the candle is in pillar form and 20-30 wt. % whenthe candle is non-pillar (i.e., placed within a jar or the like). Inpreparing a candle that contains insect repellant, ETPA is a preferredgellant.

A preferred article of the invention contains 30-60% ETDABP, 40-70%solvent, less than 50% fragrance (but at least an effective amount,typically at least about 0.1%) and less than 5% colorant (but at leastan effective amount, typically at least about 0.25%), where thesepercentage values are weight percents based on the combined weight ofthe ETDABP, solvent, fragrance and colorant. Another preferred articlecontains 10-30% ETDABP, 65-80% solvent, less than 50% fragrance (but atleast an effective amount, typically at least about 0.1%) and less than1% colorant (but at least an effective amount, typically at least about0.25%) where these percentage values are weight percents based on thecombined weight of the ETDABP, solvent, fragrance and colorant.

One aspect of the present invention provides a gelled article which isnot primarily intended to be flammable, but rather is intended tocontain an active ingredient. In one embodiment, this aspect of theinvention provides for a gelled composition that emits or otherwisemakes available to its surrounding environment one or more activeingredients of the gelled composition. Illustrative active ingredientsare fragrance materials, insecticides, insect-repellent and bioactiveingredients. In another embodiment, the active ingredient may be activewhile remaining within the gel. Examples of such active ingredientsinclude, without limitation, colorant and sunscreen. Thus, this aspectof the invention provides for air fresheners, fragrance sticks,fragranced soft gels, insect repellants, insecticides, color-deliverycompositions, sunscreens and other dermatological compositions, and thelike.

A preferred active ingredient is somewhat volatile in order that it maybe emitted and released from the gel. However, the active ingredient maybecome volatile under the conditions of use for the article. That is, ifthe article is intended to be burned, as for example a candle or fuel,then the active ingredient may become volatile under the elevatedtemperature environment caused by the burning, however it is notparticularly volatile at room temperature when the article is not beingburned. Also, an active ingredient may be emitted in that it migrates tothe surface of the gel and then comes into contact with the environment.Articles which emit an active ingredient into the environment in orderto have the desired effect may, for convenience, be collectivelyreferred to herein as controlled release compositions.

The active ingredient may be a fragrance material. Suitable fragrancematerials include fine perfumes and commodity fragrance materials, wherea large number of suitable fragrance materials are identified in Example35 herein. It has been surprisingly discovered that fragrance materialscan be combined with an ester-terminated dimer acid-based polyamide (andpreferably with ETPA as defined above) to form a composition that notonly emits fragrance, but is also homogeneous. An inhomogeneouscomposition is not desired because such compositions tend to haveerratic fragrance release profiles, i.e., they emit bursts of fragrancefollowed by periods of little or no fragrance release. Thefragrance-containing compositions of the present invention provide for acontrolled release of fragrance, i.e., a steady release of fragrancewhich lasts for a long time.

In addition, all or nearly all of the fragrance in the inventivecompositions can be released from the composition. This is highlydesirable and advantageous in comparison to some prior art compositionswhich, in contrast, hold some of the fragrance material and never allowits release into the environment.

When the fragrance material is a fine fragrance, the gelled compositionis preferably in the form of a stick, which can be rubbed onto a surfaceto provide a layer of fragrance-releasing material. Such a compositionwill be referred to herein as a fragrance stick. Alternatively, thegelled composition may be a “soft gel” by which is meant a compositionof gelatin-like consistency. A soft gel does not typically hold itsstructure under stress, and thus is preferably contained within a jar orthe like. A soft gel may be applied to the skin or other surface byimmersing a finger into the gel and then rubbing the residue from thefinger onto another area of the skin. The term “fine fragrance”generally refers to fragrances which are used in fine (e.g. expensive)perfumes. ETDABP and ETPA are both well suited for use in fragrancedsticks and soft gels because, not only can they form a stick-likeconsistency with fragrance and optional ingredients, the EPDABP and ETPAare not harmful or irritating to most surfaces, e.g., human skin.

In a typical fragranced stick or soft gel of the invention, the finefragrance is present at a concentration within the range of about 1-50wt. % of the composition, and preferably constitutes about 2-25 wt. % ofthe composition. The ETDABP or ETPA is present at a concentration withinthe range of about 5-50 wt. % of the composition, and is preferablypresent within the range of about 10-20 wt. %. Greater or lesser amountsof these ingredients may be present, depending on the desiredconsistency of the stick and the compatibility of the fragrance with theETDABP or ETPA.

ETDABP and fragrance, optionally with additional solvent, may becombined according to the invention to provide a gel structure suitableas an air freshener. Such a structure is desirable in that it providesfor a sustained and controlled release of fragrance from the mixture. Ingeneral, the gel structure becomes firmer as the concentration of ETDABPincreases in the air freshener, and can even adopt a “stick” typeconsistency, which refers to a very firm gel. The combination of ETDABPand fragrance can afford a clear or transparent structure. Such atransparent structure may increase the aesthetic appeal and applicationareas of the freshener in the marketplace.

The air freshener of this invention is prepared from components thatinclude an ester-terminated dimer acid-based polyamide (ETDABP) and afragrance, where ETPA is a preferred ETDABP. A typical inventive airfreshener contains ETDABP in a concentration range of about 5-60 wt. %,and fragrance in a concentration range of about 1-50 wt. %, where theseweight percent values are based on the total weight of the airfreshener. The amounts of ETDABP and fragrance present in the airfreshener can be varied outside these typical ranges, and still providea useful product. The precise amount of ETDABP and fragrance to be usedin preparing an air freshener will depend on the qualities of theparticular ETDABP and fragrance, as well as the desired consistency andother properties of the product.

Whether in a fragranced stick, fragranced soft gel or an air freshener,the fragrance material preferably has low polarity. Highly polarfragrance materials are not preferred because they tend to be marginallycompatible with the ETDABP or ETPA gellant, and accordingly cannot beformed into homogeneous gels having a high content of fragrancematerial. Typically, a high fragrance content is desirable in, forexample, an air freshener because such an air freshener may potentiallyhave a longer useful lifetime. Air fresheners containing ETDABP or ETPAcan typically be formulated to have higher amounts of non-polarfragrance materials than polar fragrance materials. However, theinvention includes air fresheners which incorporate fragrance materialhaving a wide range of polarities, including mixtures of fragrancematerials of any polarity.

Another active ingredient which may be incorporated into a gel of theinvention is an anti-insect chemical. The term “anti-insect chemical” isintended to encompass materials that are toxic and/or repugnant to aninsect. The gel containing the anti-insect chemical preferably has theconsistency of a stick, or at least a firm gel, and will be referred toherein for convenience as an insect stick. The insect stick of theinvention may be used to impart an anti-insect residue, in the form of athin film, to a surface. Such a residue may be placed onto the surfaceof a cupboard, for example, in order to kill and/or repel insects fromthe cupboard. Alternatively, the thin film may be applied to the skin,to repel insects such as mosquitoes from the skin.

In a typical insect stick of the invention, the ETDABP or ETPA contentwill range from about 5-60 wt. % of the stick, and preferably rangesfrom about 10-50 wt. %. The content of the anti-insect chemical willtypically range from 0.1-30 wt. %. The amount of anti-insect chemical tobe used in the insect stick will depend on the potency of theanti-insect chemical, as well as its compatibility with the ETDABP orETPA. Suitable anti-insect chemicals include boric acid, syntheticpyrethroid, D-empenthrin and DEET, as well as the other insecticidesdisclosed previously herein. Other anti-insect chemicals as known in theart may also or alternatively be incorporated into the gel of theinvention.

Another active ingredients functions primarily while being maintainedwithin the gel of the invention. Examples of such active ingredientsinclude colorant and sunscreen. When the active ingredient is acolorant, then the product may be used to impart desired coloration to asurface, and/or to hide underlying and undesirable coloration. Theactive agent may be a sunscreen, where suitable sunscreens include,without limitation, PABA, ethylhexyl p-methoxycinnamate, oxybenzone,2-ethylhexyl salicylate, octylsalicylate, and metal oxide such as zincoxide and titanium oxide. The zinc oxide and titanium oxide scatterlight so that less light hits the underlying skin.

Another active ingredient is a bioactive compound. As used herein, abioactive compound acts on a biological system to produce a desirableresult. In a preferred embodiment, the bioactive compound may be appliedto the skin of a person, to have a desirable effect on the person. TheETDABP gel of the invention thus serves as a carrier for delivering thebioactive compound to the biological system, and/or as a means to holdthe bioactive compound at a site to which it has been delivered, and/oras a repository of bioactive compound which provides for the controlledrelease of the bioactive compound to the system. The amount of this typeof active ingredient to incorporate into the composition will depend onthe desired effect, and such an amount can be readily determined by oneof ordinary skill in the art without undue experimentation. At aminimum, the amount should be an effective amount. Typically, 0.1-25 wt.%, and more typically 0.5-10 wt. % of the active ingredient issufficient, where the wt. % value is based on the entire weight of thecomposition.

The bioactive compound may be cosmetic/dermatological agent whichproduces a desirable result on the host when applied to the host's skin.Exemplary desirable results include, without limitation, anti-fungalactivity, hemorroid treatment, anti-itching treatments, wart removal orreduction, antibiotic activity, anti-wrinkling, and analgesic effects.Suitable cosmetic/dermatologic agents include, without limitation,acetylsalicylic acid, acyclovir,6-[3-(1-adamantyl)-4-methoxyphenyl]-2-naphthoic acid, amphotericin B,ascorbic acid, benzoyl peroxide, betamethasone valerate, chloroxylenol,citric acid, clindamycin phosphate, clobetasol propionate, clotrimazole,cyproheptadine, diclofenac, diphenylhydramine hydrochloride, econazole,erythromycin, estradiol, glycolic acid, glycyrrhetinic acid,hydrocortisone, hydroquinone, ibuprofen, ketoconazole, kojic acid,lactic acid, lidocaine hydrochloride, metronidazole, miconazole,miconazole nitrate, octopirox, 5-n-octanoylsalicylic acid, paracetamol,pramoxine hydrochloride, progesterone, retinoic acid, retinol, salicylicacid, superoxide dismutases, terbinafine, thenaldine, α-tocopherol,tolnaftate, trimeprazine, 1,8,10-tripropionyl-9-anthrone, undecylenate,and vitamin D.

The bioactive agent may be function as a topical analgesic, whereexemplary topical analgesics include, without limitation, camphor,capsicin, menthol, methyl salicylate, and trolamine salicylate. Thebioactive agent may function as an anti-fungal agent, where exemplaryanti-fungal agents include, without limitation, clotrimazole, miconazolenitrate, tolnaftate, and undecylenate. Exemplary anti-itching agentsinclude, without limitation, pramoxine hydrochloride anddiphenylhydramine hydrochloride. An exemplary anti-wart compound forincluding in a gel of the invention is salicylic acid. An exemplaryhemorroid treating compound for including in a gel of the invention ishydrocortisone. An exemplary antibiotic compound for including in a gelof the invention is chloroxylenol.

The bioactive agent may function as a wound-healing aid for preventingand reducing injury to mammalian cells and increasing the resuscitationrate of injured mammalian cells, where an exemplary wound-healing aid isa combination of (a) pyruvic acid and pharmaceutically acceptable saltsthere of, and (b) a mixture of saturated and unsaturated fatty acidsrequired for the repair of cellular membranes and resuscitation ofmammalian cells. The bioactive agent may be an antioxidant, whichinhibits oxidation or supression reactions promoted by oxygen orperoxides, where exemplary antioxidants include, without limitation,vitamin A, vitamin E, and derivatives thereof. The bioactive agent mayfunction as an anti-acne agent. Exemplary anti-acne agents include,without limitation, benzoyl peroxide and vitamin A acid.

The amount of bioactive ingredient to incorporate into the gel of theinvention will depend upon the efficacy of the bioactive ingredient andthe desired effect. This amount can be determined by one of ordinaryskill in the art without undue experimentation. At a minimum, the amountshould be an effective amount. Typically, 0.1 wt. % to 25 wt. %, andmore typically 0.2 wt. % to 10 wt. % of bioactive ingredient issufficient.

The gels of the present invention containing an active ingredient mayadditionally contain optional ingredients. The optional ingredients mayserve one or more purposes, such as to facilitate the formation of ahomogeneous gel, enhance the delivery properties of the product,increase the aesthetic appeal of the product, enhance the ability of theproduct to release active ingredient, etc.

One suitable optional ingredient is a colorant. The addition of colorantto an air freshener may enhance the aesthetic appeal of the product. Theaddition of colorant to a gel which will be applied to skin or othersurface will provide a marker so that the residue of the gel will bevisible on the surface. A preferred fragranced stick or gel, absent thecolorant, is clear and transparent, although the fragranced stick orsoft gel of the present invention may be opaque or translucent. In anyevent, the addition of colorant may enhance the visual appeal of thefragranced stick or gel, and the residue provided when the stick or gelis rubbed across a surface. The colorant may be a dye or a pigment, andis preferably non-irritating to the skin when the gel will be applied toskin. Such colorants are well known in the art, and are used in, forexample, cosmetics such as lipstick and eye shadow.

When present, the colorant is typically needed in only small amounts,for example, less than 5 wt. %, and often as little of 1 wt. % or even0.1 wt. % is sufficient to impart a desired coloration to the gel. If amore intense coloration is desired, then the amount of colorant in thegel may be increased. When coloration is desired, the colorant should bepresent in an amount effective to provide the desired coloration.

Other optional components may serve to enhance the processing of the gelwith the active ingredient. For example, the optional component mayfacilitate formation of a homogeneous mixture between the ETDABP or ETPAgellant and the active ingredient. In addition, the optional componentwill typically influence the consistency of the gel, and can be used toimpart enhanced delivery properties to the stick or gel. For instance,the incorporation of volatile hydrocarbon has been found to enhance thehomogeneity of the gel-active ingredient combination, as well as promotethe delivery of a thin layer of gel to the skin, with the absence of aconcomitant wet residue that might otherwise be present.

A preferred optional component is a volatile hydrocarbon, where apreferred volatile hydrocarbon is a C₁₀-C₁₈ chemical formed entirely ofcarbon and hydrogen. The carbon atoms may be arranged in a linear,branched or cyclic structure, and unsaturation may be present betweenany two carbon atoms. Suitable volatile hydrocarbons include C₁₁-C₁₅paraffinic and isoparaffinic compounds, including mixtures thereof.Exxon Chemical (Houston, Tex.) sells suitable volatile hydrocarbonsunder their Isopar® L and Isopar® M trademarks. The volatile hydrocarbonis preferably odorless, and has only a slight vapor pressure.

If sufficiently volatile, the optional component may also serve to carryactive ingredients from the gel and into the environment. A preferredvolatile optional component is a volatile hydrocarbon, however othervolatile materials such as ethers and esters could also be used. Themolecular weight and vapor pressure of the volatile optional componentmay be selected with a view to its effect on the release properties ofthe anti-insect chemical. As the volatility of the volatile optionalcomponent increases, the volatile optional component will tend to carrymore of the active ingredient to the surface of the gel, thereby makingthe active ingredient more available to the environment. A preferredvolatile optional component is a volatile hydrocarbon, e.g., a C₁₀-C₁₈volatile hydrocarbon.

When present, the volatile optional component constitutes about 5-90 wt.% of the stick or soft gel, and preferably constitutes about 10-50 wt.%. The amount of volatile optional component in the gel may be higher orlower than these typical ranges, depending on the desired consistency ofthe stick, the precise chemical composition of the volatile optionalcomponent, ETDABP or ETPA, and bioactive ingredient, and the presence ofother optional components.

Another suitable optional component is a mineral oil. The mineral oilmay be used to increase the pay-off of the stick or soft gel. The term“pay-off” refers to the amount of residue that is delivered to a surfacewhen the stick, or a finger having a residue of soft gel, is rubbedacross that surface under a typical pressure. Thus, the ideal stick orsoft gel should have a pay-off which is neither too little nor toogreat. The pay-off of a stick or gel can typically be increased byincreasing the amount of mineral oil in the composition. However, if toomuch mineral oil is present, then the composition provides an unpleasantgreasy feel to the residue. The combination of mineral oil with volatilehydrocarbon may be used to provide desirable rub-off and non-greasy feelto sticks and soft gels of the present invention, and is a preferredcombination that may be gelled with ETDABPA and ETPA according to theinvention.

Another ingredient which may be used to increase the pay-off of thestick or gel is a fatty ester. The fatty ester may also be serve toprevent drying of the skin which is contacted with the fattyester-containing gel of the invention. Such fatty esters are commonlyused in skin lotions and the like, and thus are known to those of skillin the art. Suitable fatty esters include the esters of C₁₀-C₂₂ fattyacids and mono- or poly-hydric alcohols. Exemplary fatty acids include,without limitation, myristic acid, sebacic acid, oleic acid, palmiticacid and the like, and exemplary mono- and poly-hydric alcohols include,without limitation, C₁-C₂₂ monohydric alcohols such as methanol,2-ethylhexanol, decanol, and hexadecanol, C₂-C₂₂ dihydric alcohols suchas ethylene glycol, polyethylene glycol, neopentyl glycol, and C₃-C₂₂trihydric alcohols such as glycerol.

A hydrocarbon having a relatively high number of carbon atoms, forexample squalene or other skin oil, may also be desirably includedwithin the stick or soft gel of the invention if the product will beused to contact the skin. The skin oil may reduce any irritation thatcould arise when the skin contacts the active ingredients, e.g.,anti-insect chemical or bioactive ingredient, present in the gel.

The composition of the invention may be prepared by combining ETDABPwith the active ingredient(s), and heating these with stirring until auniform mixture results. Upon cooling, the mixture will assume a gel orstick-like consistency. One or more solvents as described above may alsobe present in the composition.

If an optional hydrocarbon component is to be present in thecomposition, then a preferred method of preparing the controlled releasecomposition is to heat the hydrocarbon and the ETDABP or ETPA gellantwith stirring until a homogeneous mixture results. Typically, this isachieved within a temperature range of about 80-120° C. While highertemperatures may be employed, no benefit arises as a result of suchhigher temperatures. After the molten homogeneous mixture of hydrocarbonand gellant is formed, the mixture may be cooled before adding theactive ingredient(s). This pre-cooling step is particularly preferredwhen the active ingredient is volatile, and is less important fornon-volatile active ingredients. After stirring the active ingredient(s)into the composition, the composition is allowed to cool whereupon a gelforms.

ETDABP in combination with one or more solvents, and optionallycontaining one or more additional ingredients such as fragrance orbioactive ingredient, may form a transparent, rigid and stable gel.These gels may be used to form flammable objects (e.g., candles andfuels), or objects that contain and/or emit active ingredients. The gelsof the present invention are particularly desirable because theydemonstrate each of the properties of transparency, rigidity andstability, which cannot be said of the prior art gels. Before describingthe various ways in which ETPA may be formulated to provide desirablegels of the invention, some discussion regarding each of transparency,rigidity and stability in the context of the present invention isprovided.

As used herein, the term “rigidity” refers to the amount of deflectionwhich a gel displays when responding to a force. More specifically, arigidity may be measured by holding a cylinder (or similar shape) of gelmaterial in a horizontal direction. The extent to which the cylinderbends toward the earth under the force of gravity is used as a measureof the rigidity of the gel. A very rigid gel will not bend to anynoticeable degree, while a gel that exhibits little or no rigidity willdisplay considerable bend.

In order to impart quantitative meaning to the term “rigid”, the testdescribed below has been devised, which provides a measure of rigidityin terms of a “deflection value”. The deflection values may range from aminimum of zero to a maximum of 90, where completely rigid material doesnot show any deflection and thus has a deflection value of zero, while avery flexible/limp material will show the maximum deflection and bedescribed by a deflection value of 90.

The testing protocol is illustrated in FIG. 5. A gel sample havingdimensions 57×10×3 mm is placed on a flat horizontal surface, such that10 mm of the sample is on the surface and the remainder of the sampleextends over the side of the surface and is unsupported. The degree towhich the unsupported portion of the sample bends downward provides thedeflection value. Thus, if the sample does not bend downward at all, itis assigned a deflection value of 0, because the unsupported portion isdirected at an angle of 0° different from the supported portion of thesample. However, if the unsupported portion of the sample bends straightdownward as soon as it is unsupported, then this sample has a deflectionvalue of 90 because the unsupported and supported portions form a 90°angle with respect to each other. A material with a lower deflectionvalue, which corresponds to a material with higher rigidity, is mostdesirable for a candle.

Using this test, gels formed from ETPA and hydrocarbon oil may have adeflection value of essentially zero (0), while a gel formed fromKraton® according to the prior art has a deflection value of about 80.If some flexibility (i.e., non-rigidity) is desired in an objectaccording to the present invention, it can be achieved by appropriateselection of the gellant and solvent. Thus, the present inventionprovides gels having deflection values of less than or equal to 70, morepreferably less than or equal to 60, still more preferably less than orequal to 50, yet more preferably less than or equal to 40, and stillmore preferably less than or equal to 30, yet still more preferably lessthan or equal to 20, further still more preferably less than or equal to10, and further still more preferably less than or equal to 5, and mostpreferably equal to or essentially equal to zero. As the deflectionvalue of the gel increases, a candle prepared from such a gel can form afree-standing pillar shape, which will not flop over at the slightest(or even a significant) touch.

Not only may the ETPA gels of the present invention be formulated suchthat they are rigid, they may also simultaneously be transparent. Thereare various degrees of transparency, ranging from crystal clear to hazy,which may be achieved with gels of the invention. In order to providesome measure of the absolute transparency of a gel, the following testhas been devised. A white light is shined through a gel sample of agiven thickness at room temperature, and the diffuse transmittance andthe total transmittance of the light are determined. The percent hazefor a sample is determined by the equation: % haze=(diffusetransmittance/total transmittance)×100. Samples are prepared by meltingthe gel (or product made therefrom) and pouring the melt into 50 mmdiameter molds. The samples may be prepared at two thicknesses, e.g.,5.5±0.4 mm and 2.3±0.2 mm.

Clarity measurements are made on a Hunter Lab Ultrascan SphereSpectrocolorimeter using the following settings: specular included, UVoff, large area of view, illuminate D65, and observer 10°. Using thisprotocol with a 2.3 mm thickness sample, an ETPA gel of the presentinvention may have a % haze value of less than 5, while paraffin wax hasa % haze value of over 90. The % haze value for a gel of the presentinvention can be increased if desired, by appropriate selection ofsolvent and gellant. Thus, the present invention provides gels (andarticles made therefrom) having a transparency (measured by % haze) ofless than 75, preferably less than 50, more preferably less than 25,still more preferably less than 10, and yet still more preferably of 5or less.

The gels of the invention are also stable, in that they preferably donot display syneresis. As defined in the McGraw-Hill Dictionary ofScientific and Technical Terms (3^(rd) Edition), syneresis is thespontaneous separation of a liquid from a gel or colloidal suspensiondue to contraction of the gel. Typically, syneresis is observed as theseparation of liquid from a gel, and is sometimes referred to as“bleeding”, in that wetness is seen along the surfaces of a gel thatdisplays syneresis. From a commercial point of view, syneresis istypically an undesirable property, and the gels of the present inventiondesirably, and surprisingly do not exhibit syneresis.

The gels of the invention, and articles prepared therefrom, may bestable in the sense that they do not exhibit syneresis. Thus, they do nohave an oily feeling when handled. Furthermore, they have little or nottendency to flare when lit, due to the presence of a pool or coating ofa flammable liquid which has been exuded due to syneresis.

The ETDABP or ETPA gels as described above (as well as additional gelsdescribed below) may be encased in whole or part by a solid coating. Asused herein, the term encased means “covered by”, so that an article atleast partially encased by a coating has a coating overlying at leastsome of the gel. The coating preferably directly contacts the exteriorsurface(s) of the gel. The coating may be present when the gelledarticle is primarily intended to be burned, or on a gelled article whichis intended primarily to emit or contain an active substance. Thecoating may confer one or more of a number of possible benefits to thegel.

For instance, any oily feel that may be sensed upon handling the gel iseliminated when a coating is placed on the gel. The coating typicallyhas a non-oily feel, and in fact typically feels dry to the touch. A gelabsent the coating will tend to pick up fingerprints when it is handled.The coating does not so readily receive fingerprints, and thus theinvention provides that a gel may be repeatedly handled by a consumerwithout leaving telltale fingerprints, so long as the gel contains acoating as described above.

In addition, the coating typically imparts some mechanical strength tothe article, which would not be present in its absence. Gels are oftensomewhat soft, and may benefit from the increased mechanical strengthduring, for example, shipping and storage of the article.

The coating may also enhance the clarity of the gelled body by impartinga rigid yet very smooth surface to the body. The coating may be made tobe extremely smooth and to have a highly polished appearance. Even whenthe underlying gel itself is transparent, the surface of the gel may notbe completely smooth, in part due to a degree of softness that istypically present in a gel. However, when a hard transparent coating isplaced on the surface of a gel, then a very smooth and flawless exteriorsurface can be achieved. This smooth surface imparts a greaterappearance of clarity to the gel. The transparent coating may alsoimprove the refractive index of the exterior of the gel. Thus, even ifthe gelled body does not appear totally transparent, the addition of thecoating can improve the transparent appearance of the article. In anyevent, the presence of a transparent coating is highly desirable inorder to prepare a transparent candle or other gelled article of thepresent invention.

When the gel has been formulated primarily for the purpose of emittingan active substance, the coating may be used to effect the rate at whichthe active ingredient(s) is released and contacts the surroundingenvironment. For instance, the coating may be used to inhibit therelease of the active ingredient, so that a smaller yet still effectiveamount of active ingredient contacts the environment for a longer periodof time. Thus, the coating, besides improving the appearance and feel ofa gelled article, can also control the release of volatile fragranceingredients from a gel. For example, a highly crosslinked thermosettingcoating such as an epoxy may be used to slow the release rate ofvolatile fragrance ingredients from a gelled fragrance release device,which would increase the service life of this article. Thecharacteristics of the coating, such as the chemical functionality andfree volume, and the manner in which the coating is applied, includingthe coating thickness and the area of gel coated, may be varied tocontrol the release rates of various fragrance ingredients from thegelled article.

The coating is preferably clear and colorless or essentially colorless.In addition, the coating is solid, preferably not brittle, and yet notso soft that it is easily deformed after application to the gelled body.The coating may contain optional ingredients, such as colorant,fragrance, UV-inhibitors, antioxidants, insect-repellents, and the like.

In a preferred embodiment, the coating includes thermoplastic polymer. Apreferred thermoplastic polymer is a polyamide resin formed from dimeracid and diamine, and possibly optional components. The dimeracid-containing (or “based” resins are commercially available from manysources, including Union Camp Corporation, Wayne N.J. under the UNI-REZtrademark, and Henkel Corporation, Ambler, Pa. under the MACROMELTtrademark. They are essentially the reaction product of polymerizedfatty acid as described above, and diamine. Optional reactants includemonoamine, diacid other than polymerized fatty acid, refined trimeracid, monocarboxylic acid, and others known in the art. Because thesepolyamides have been sold commercially for about 50 years, and are wellknown in the art, the following description of dimer acid-basedpolyamides is abbreviated.

Dimer acid-based polyamides are the reaction product of dimer acid asdefined above, with diamines. The term “diamine” refers to a moleculehaving two amine groups, where the amine groups are both preferablyprimary (e.g., ethylene diamine, hexamethylene diamine, ether diamines,etc.), however may be secondary (e.g., piperazine). The molecular weightof the polyamide will depend, in part, on the relative amounts of dimeracid and diamine used in its formulation. The addition of monofunctionalacids (e.g., stearic acid, oleic acid, isostearic acid, etc.) ormonofunctional amines may also be used to form low molecular weightpolyamides. The dimer acid may be hydrogenated or non-hydrogenated, andco-diacids such as azeleic, sebacic, etc. may be used in the formationof the polyamide

In general, a low molecular weight dimer acid-based polyamide is apreferred coating component, and is more preferably the only componentof the coating. Such low molecular weight polyamides are preferredbecause they typically achieve a low viscosity molten state at arelatively lower temperature then may be achieved from high molecularweight polyamides. In addition, the solubility of a dimer acid-basedpolyamide in an organic solvent typically increases as the molecularweight of the polyamide decreases. However, polyamides tend to becomemore brittle as their molecular weight decreases, and so a balancebetween brittleness and melt viscosity/solubility properties ispreferably attained. Uni-Rez® 2620 polyamide resin (Union CampCorporation, Wayne, N.J.) at 20-40% solids in n-propanol is a suitablesolution from which to form a coating on a gelled article of theinvention. Solvents other than n-propanol, e.g., n-butanol orisopropanol to name two, could also be used. Such a solution may beapplied to the gelled body at room temperature or slightly above roomtemperature, for example 30-40° C.

The thermoplastic need not be a polyamide. Another suitablethermoplastic is a styrene-acrylic resin. Such resins are commerciallyavailable and are used in applications such as inks and floor polishes.S.C. Johnson of Racine, Wis., Air Products of Allentown, Pa. and Rohmand Haas of Philadelphia, Pa. are three of the many commercial suppliersof styrene-acrylic resins. Again, a resin with a relatively lowmolecular weight is preferred, as it allows for a lower viscosity in alow temperature molten state, and generally has higher solubility inorganic solvents.

In another preferred embodiment, the coating may include a thermoset.However, the thermoset needs to have a sufficiently long pot life toenable the coating to be applied to the gelled body before the coatingcures. The thermosetting system may be a two component system that iscured by mixing two reactive species such as an epoxy cured with apolyamine or polyamide. Alternatively, the thermoset may be a onecomponent system that is cured by water vapor (e.g., a moisture-curableurethane) or electromagnetic radiation (e.g., a UV-curable acrylate orpolyamide, etc.), to name two preferred one component thermosetscharacterized by their curing agent.

Additional polymers from which a suitable coating for the gelled articleof the invention may be formed include, without limitation, polyolefins,polydienes, polyamides, polyurethanes, polyimides, polyesters,polyamide-imides, polyester-imides, polyester-amides, polyketones,polyvinyl acetals, polyvinyl ethers, polyureas, acrylics, alkyds, aminoresins, cellulosics, elastomers, epoxies, fluoropolymers, ionomers,maleics, natural resins, oleoresinous varnishes, petroleum resins,phenolics, pine derived resins, Shellac, silicones, styrene resins,vegetable and marine oils, vinyl acetate resins, and vinyl chlorideresins.

The coating, whether it contains a thermoplastic or thermoset resin orpolymer, may additionally contain one or more optional ingredients. Acolorant is a preferred optional ingredient. Colorants as describedpreviously for incorporation into a gelled body may equally well beincluded in the coating composition. A UV-inhibitor is another optionalingredient. Thus, a UV-inhibitor may be added to the coating to that thecoating effectively protects the entire gelled body from UVradiation-induced degradation.

While the present invention provides ETDABP gels at least partiallyencased by a solid coating, the invention also provides for coated gelsmade form gellants other than ETDABP. Suitable gellants are known in theart, and representative examples as described below. The solvents whichare used in these prior art gels may also be used as the solvent forpreparing a gel using ETDABP as the gellant. Furthermore, the materialwhich is coated according to the present invention need not even be inthe form of a gel, but can be a solid, such as a wax. Suitable waxesinclude paraffin wax and polyethylene wax.

For instance, a gel may be prepared by combining a polyamide resin (agellant) with an oil (a solvent) as described in U.S. Pat. No. 3,645,705to Miller et al. As set forth in Miller, the polyamide resin may be along chain linear amide resin derived from the reaction of dimerizedlinoleic acid with di- or polyamines. The polyamide resin typically hasa molecular weight (number or weight average) in the range of 6,000 to9,000 and a softening point in the range of 48° C. to 185° C., and iscapable of producing a gel structure in oil when the solubility of thepolyamide in the oil is exceeded. The polyamide resin typicallyconstitutes about 7-50% of the total weight of the gel. The oil may be anatural oil, such as castor oil, peanut oil, safflower oil, sunfloweroil, corn oil or cod liver oil, having an iodine value in the range of40 to 135. The oil may be a light, clear mineral oil. The article isreadily formed by combining the various constituents at elevatedtemperature until a homogeneous mass is formed, and then cooling themass to provide a gelled body.

Up to about 15% by weight of a methyl ester, such as methyl ricinoleateor methyl oleate, may be added to the composition to improve thestiffness and hardness of the article. An 8-, 10- or 12-carbon primaryalcohol may be included within the composition that forms the gel, wherethe alcohol may serve to overcome a greasy or oily surfacecharacteristic that the gel would otherwise have. The percentage ofalcohol by weight should not be more than about 30% of the totalmaterial, the preferred range being 10-20%. As an article according tothis aspect of the present invention has a coating on at least a portionof the surface of the gelled body, and this coating is intended, inpart, to provide a pleasing, non-greasy surface to the gel, theincorporation of a primary alcohol in the formulation is not necessary.

Alternatively, the gel may be formed according to Gunderman et al., asset forth in U.S. Pat. No. 3,819,342. Thus, a thermoplastic polyamideresin and a solvent may be combined to form a gel. The polyamide resinis preferably formed by the reaction of an aliphatic polycarboxylic acidwith a di- or polyamine. Most preferred are the reaction products ofdimerized linoleic acid with di- or polyamines. These resins have anaverage molecular weight of between 2,000 to 10,000 and are described ingreat detail in U.S. Pat. Nos. 2,379,413 and 2,450,940.

The solvent of Gunderman et al. is capable of solubilizing thethermoplastic polyamide resin at a temperature below about 100° C., andis selected from the group consisting of unsaturated fatty acids,unsaturated fatty alcohols, saturated fatty alcohols, esters of fattyacids with polyhydric alcohols such as glycerol, and mixtures thereof.Specific suitable solvents include oleyl alcohol, linolenyl alcohol,palmitoelyl alcohol, linoleyl alcohol, mixtures thereof and the like.C₆-C₁₄ alcohols such as decanol dodecanol, hexanol, heptanol, octanol,nonanol and tetradecyl alcohol, and/or C₁₀-C₂₂ fatty acids such asricinoleic, oleic, linolenic, erucic, decylenic, dodecylenic andpalmitoleic acids may be employed as the solvent. An ester such ascaster oil, coconut oil derivatives, propylene glycol monolaurate,propylene glycol stearate, propylene glycol myristate and the like, maybe used as well.

The polyamide and solvent of Gunderman et al. are combined in such aratio that a gel results. For optimal performance, the article shouldcontain from about 5 to 35 parts by weight of the thermoplasticpolyamide resin. A preferred composition is one utilizing such a rangeof resin with an equivalent amount of oleyl alcohol. The article isreadily formed by mixing the ingredients at elevated temperature to forma homogenous composition, and allowing the composition to cool to a gelstate.

Alternatively, the gel may be prepared according to U.S. Pat. No.3,615,289 to Robert Felton. Thus, a gel may be formed by combining asolid polyamide resin, an alkanol amine or alkanol amide, and one ormore stearic acid esters or a mixture of stearic acid esters and stearicacid. The composition comprises about 15 to 35 percent by weightpolyamide resin, about 20 to 55 percent by weight of alkanol amine oralkanol amide, and about 1 to 50 percent by weight of stearic acid andesters thereof. The gels of Felton are readily formed by heating thecomponents with stirring at a temperature of about 100-115° C. until themixture is clear, and then allowing the mixture to cool to a gelledstate.

The solid polyamide resin of Felton is the soluble condensation productof an aliphatic dicarboxylic acid and a diamine, the carboxyl and aminogroups of adjacent monomer units being condensed to an amide linkage inthe resin. The resin may also be based on carboxylic and amine compoundshaving more than two carboxyl and amino groups respectively. The resinis composed primarily of polyamides of molecular weight within the rangeof from about 2,000 to about 10,000, and are of the type generally setforth in U.S. Pat. No. 2,450,940. The alkanol amide may be prepared bythe reaction of a fatty acid ester and an amine, wherein the ester andthe amine are in substantially equal proportions. Among such compoundsare the 1:1 and 2:1 (Kritchevsky type) diethanolamides of fatty acids,the 1:1 proportion being preferred. The preferred chain length for thefatty acid is about 14 to 24 carbon atoms. Suitable esters of stearicacid include isopropyl isostearate, butyl stearate, hexadecyl stearate,etc.

The gelled articles (candles) of Felton may contain a polyamide resinhaving at least some free carboxylic acid groups so that the polyamideresin has reactive character. This component may be present in aproportion of from about 5 to 10 percent by weight of the composition,and acts to prevent “sweating” by inhibiting the migration of the oilcomponents. It also provides a smoother, glossier finish to the gelledbody. This reactive polyamide may, but need not be present in thearticles of the present invention, because the coating on articles ofthe present invention achieves the desired surface appearance and feelof the article, without reliance on the reactivity of the polyamide.

As a further alternative, the gel may be prepared by the procedures andreactants set forth in U.S. Pat. No. 5,578,089 to Mohamed Elsamaloty.According to Elsamaloty, a gel may be prepared from a hydrocarbon oil (a“solvent” of the present invention) and a blend of diblock and triblockcopolymers based on synthetic thermal plastic rubbers. The hydrocarbonoil may be a cosmetic grade hydrocarbon oil (natural or synthetic) andis preferably a white oil. The oil may be a paraffinic oil, a naphthenicoil, natural mineral oil or the like. The rubber blend is prepared fromat least one diblock and at least one triblock copolymer, in addition toone or more of radical copolymers and multiblock copolymers. Kraton®rubbers from Shell Chemical Company, which includestyrene-butadiene-styrene copolymers and styrene-isoprene-styrenecopolymers, are preferred. The gel is formed by blending the polymersand the oil, and then heating the blend to between about 50-90° C. todissolve the polymers in the oil. Mixing may be carried out in anyconventional manner. On cooling, a gel forms.

In one embodiment, the gel preferably consists of about 80-99 wt. %hydrocarbon oil and about 1-20 wt. % of a blend of rubbers, where therubbers are a blend of at least two different polymer members selectedfrom the group consisting of diblock copolymers, triblock copolymers,radial block copolymers and multiblock copolymers, the gel including atleast one diblock copolymer comprising segments of styrene monomer unitsand rubber monomer units. In another embodiment, the gel comprises fromabout 70% to about 98% by weight of a hydrocarbon oil, from about 2% toabout 30% by weight a copolymer selected from the group consisting of atriblock, radial block and multiblock copolymer, and from 0 to about 10%by weight of a diblock copolymer, as described in, e.g., InternationalPublication No. WO 97/08282.

As disclosed above, there are numerous compositions from which to form agelled body comprising a gellant and a solvent, where the disclosureabove is merely exemplary. Regardless of how the gelled body is formed,and regardless of its composition, in one aspect the present inventionprovides for an article comprising a gelled body having a solid coatingon at least a portion of the surface thereof, where the coatingpreferably includes at least one of thermoplastic polymer of thermosetpolymer. The coating is not of exactly the same composition as theunderlying fuel or gel.

The coating can be placed on the gelled body by various techniques. Forexample, the coating composition may be solid at room temperature butliquid at elevated temperature. In this case, the coating compositionmay be taken to a molten state and then gelled body dipped brieflytherein, to thereby adhere a layer of coating onto the surface of thebody. When the coating composition is soluble in a solvent, then asolution of the coating composition may be prepared and the solutionapplied to the surface of the gelled body by, e.g., spraying or brushingat, e.g., room temperature. Alternatively, the gelled body may be dippedinto the coating composition solution. Normal propanol is a suitablesolvent for thermoplastic polymers as discussed above. When the coatingcomposition is applied in the absence of a solvent, it will be referredto as a neat coating composition or a solvent-free coating composition.

When a neat coating composition is applied to the surface of a gelledbody, the coating composition should have a melting point that is aboveroom temperature since the coating must be a solid at room temperature.However, the melting point of the coating composition should not be toofar above the melting point of the gelled body since dipping the gelledbody into a very hot coating composition might melt or otherwise degradethe gelled body. Thus, the identity of the neat coating composition willdepend, to some extent, on the identity of the gelled body. In addition,when a neat coating composition is employed to form the article, theviscosity of the molten coating composition should be low enough thatthe gel can easily be dipped, without significant resistance due to theviscoelasticity of the coating composition.

When a coating composition solution is to be applied to the gelled body,it is preferred that the solvent or solvents be sufficiently volatilethat the coating dries in a reasonable amount of time. Also, the choiceof solvent(s) will effect the degree to which the coating compositionwets the surface of the gelled body, and thus the solvents should beselected with this point in mind. The ability of various solvents to wetvarious surfaces has been extensively studied and published in the openliterature, and thus one of ordinary skill in the art is aware of how toselect appropriate solvents depending on the identity of the gelledbody. In general, aqueous solvents tend not to wet the gelled body,while short chain alcohols, such as n-propanol and iso-propanol, arequite satisfactory. An aqueous dispersion of a resin may be used as acoating solution, however typically some wetting-enhancement additive,e.g., n-propanol, must be added to provide for good coating of thegelled body by the aqueous coating composition.

The coating thus preferably directly contacts the exterior surface ofthe underlying gel and at least partially encases that gel. Where thegel has a top, a bottom and one or more sides, the coating preferablycovers all of the sides of the gel, and optionally the top and bottom.The coating preferably covers all of the sides of the gel because thisis the area of the gel which is primarily seen by the consumer. Thecoating should conform to the exterior surface of the gel, in that thecoating is in direct contact with all of the surface which is covered bythe coating. If the gel has a patterned exterior surface, e.g., reliefimages or a ribbed texture, then the coating either follows the exactcontours of the pattern so that the exterior surface of the coatinglikewise contains that (or perhaps a different) pattern, or that portionof the coating which directly contacts the gel will be conformal inexactly following the contours of the gel's surface but the exteriorsurface of the coating is smooth and without pattern. Where the exteriorsurface of the coating is smooth but the exterior surface of the gel hasa relief image, the coating should be transparent so that the underlyingrelief image can be viewed through the coating.

In forming an article comprising a gel having a coating thereonaccording to the present invention, it is most convenient to first formthe gel, and then apply the coating to the surface of the gel. As analternative, the solid coating may be prepared first, and the molten gelmay be poured into the solid coating. For example, the material whichforms the solid coating may be applied to the interior surfaces of amold, and then the molten mixture of gellant and solvent poured into thecoating-lined mold. If the solid coating has sufficient structuralintegrity, it may formed into a desired shape, and the molten mixture ofgellant and solvent poured therein.

The gelled bodies of the present invention, with or without coatingsthereon, may be used in industrial products such as fuels (sterno,candles, lighters). For example, hydrocarbon gelled with an ETDABPgellant may be used as a heat source in, e.g., a cooking apparatus usedin camping and hiking. Such a composition will not flow if tilted, andthus may be safer and neater than similar products made from flowingmaterials. When the product does not have a coating, then the gellant ispreferably an ETDABP, and more preferably is an ETPA gellant.

The flammable articles of the present invention may or may not include asolid coating. In some respects, the presence of a solid coating isdesirable because it adds to the mechanical strength of the article,where enhanced mechanical strength is desirable during shipping andstorage of the flammable article. In addition ,the solid coatingessentially eliminates any oil feeling and fingerprinting on the candle,and effectively reduces syneresis because the coating effectively holdsin any oils that may tend to leach out of the gelled body due tosyneresis. The solid coating may additionally contain one or more offragrance, insect-repellent. UV-inhibitor and anti-oxidant. Also, thesolid coating may contain a pattern, e.g., a relief image, which adds tothe aesthetic appeal of the coated article.

The ETDABP gellant may be incorporated into commercial products such asthose listed above by blending the ETDABP gellant with the othercomponents of the produce. Typically, the ETDABP gellant will be presentat a concentration of about 1% to about 50% of the composition, based onthe total weight of the composition. It is a routine matter to optimizethe amount of ETDABP gellant to have present in a composition, andindeed the amount will vary depending on the actual product and thedesired consistency of the product. In general, as more gellant is usedin a formulation, the gelled body will display a more pronounced gelcharacter.

The following examples are set forth as a means of illustrating thepresent invention and are not to be construed as a limitation thereon.

In the following Examples, softening point was measured using a ModelFP83HT Dropping Point Cell from Mettler Instruments Corporation, with aheating rate of 1.5° C./min. Viscosity measurements were made using aModel RVTD Digital Viscometer from Brookfield Engineering Laboratories,Inc., and are reported in centipoise (cP). Gel clarity and hardness wereboth judged qualitatively.

In the synthesis Examples that follow, and unless otherwise noted, thechemicals were all of reagent grade, obtained from commercial supplyhouses including Aldrich Chemical Co. (Milwaukee, Wis.) and the like.Unidyme® 14 polymerized fatty acid is a dimer acid available from UnionCamp Corp., Wayne, N.J. Empol® 1008 polymerized fatty acid is a dimeracid available from Henkel Corporation, Ambler, Pa. Pripol™ 1008polymerized fatty acid is a dimer acid available from Unichema NorthAmerica, Chicago, Ill. Harchemex® (Union Camp Co., Wayne N.J.) alcoholis a 60/40 blend of C₁₄/C₁₆ linear alcohols. As used herein, “BBA”stands for the company Bush Boake Allen, located in Montvale, N.J.

EXAMPLES Example 1 ETPA from C₁₄-C₁₆ Linear Alcohol

The Example shows that a clear, soft gel can be made with an ETPAsynthesized from a blend of linear alcohols having chain lengths of 14and 16 carbons

The components and amounts thereof as shown in Table 1 were charged to areaction vessel and heated at 200-220° C. under a nitrogen atmospherefor 2 hours. The resulting ETPA had a softening point of 68.5° C. and aviscosity of 44 centipoise at 130° C., as summarized in Table 2.

TABLE 1 REACTANTS USED TO FORM A LINEAR C14/C16 ALCOHOL-TERMINATEDPOLYAMIDE. Reactant % Equivalents Weight % Unidyme ® 14 100 65.6Hexamethylene diamine 50 6.5 Harchemex ® 50 27.8

This ETPA was combined with tetradecane (20 wt. % ETPA/80 wt. %tetradecane) and heated until the ETPA dissolved in the tetradecane.Upon cooling to room temperature, the solution formed a soft clear gel,summarized in Table 2.

Example 2 ETPA from C₂₂ Linear Alcohol

This example shows that a clear, soft gel can be made with an ETPAsynthesized from a linear alcohol having a chain length of 22 carbons.

The starting materials used to prepare the ETPA are identified in Table3 and the properties of the resulting ETPA are given in Table 2. Thegellant and the gel were made in the manner described in Example 1.

TABLE 3 REACTANTS USED TO FORM A LINEAR C₂₂ ALCOHOL-TERMINATED POLYAMIDEReactants % Equivalents Weight % Pripol ™ 1009 100 56.6 Hexamethylenediamine 40 4.6 Behenyl alcohol 60 38.8

Example 3 ETPA from C₁₈ Linear Alcohol

This example shows that a clear, soft gel can be made with an ETPAsynthesized from a linear alcohol having a chain length of 18 carbons.

Using the reactants identified in Table 4, and ETPA was synthesized bycharging the diacid and alcohol to a reaction vessel at roomtemperature, heating the mixture under nitrogen to 80° C., adding thediamine, heating to 220° C., holding at 220° C. for 1 hour, and finallyholding under vacuum (8-10 mbar) at 220° C. for 2 hours. As summarizedin Table 2, the ETPA had a softening point of 85.7° C. and a viscosityat 190° C. of 27 cP.

TABLE 4 REACTANTS USED TO FORM A LINEAR C₁₈ ALCOHOL-TERMINATED POLYAMIDEReactant % Equivalents Weight % Empol ® 1008 100 71.9 Ethylene Diamine65 4.8 Stearyl Alcohol 35 23.3

A gel was formed from this ETPA according to the procedure described inExample 1. As characterized in Table 2, the gel was clear and hard.

A second gel was formed from this ETPA by combining 60 weight percentETPA with 40 weight percent mineral oil, heating the mixture tohomogeneity, and then cooling to room temperature to form a gelled body.The gelled body was clear, however somewhat soft, with a melting pointof 95° C. A wick was place din the gelled body to form a candle. Uponburning, the candle had a flame height of 0.5 inches, a pool size of 1.5inches (pool size is the diameter of the pool of molten candle that ispresent at the point where the wick enters the gelled body), andexhibited some coking and the burned area exhibited slightdiscoloration.

A third gel was formed from 45 parts ETPA, 50 parts mineral oil(Drakeol® 7 from Penreco) and 5 parts fragrance (product number564-24392 from Bush Boake Allen of Montvale, N.J.). This gel was coloredwith 0.001% Pylakrome Red (Pylam Products, Tempe Ariz.) in mineral oil,to provide a crystal clear candle with excellent consistency.

A fourth gel was formed from 45 parts ETPA, 49.7 parts mineral oil, 5parts fragrance (produce number 564-24392 from Bush Boake Allen ofMontvale, N.J.). A wick was then added. The results was a slightlytranslucent candle which, after being placed in the sun for 1 hour,emitted a glow in a darkened space for at least 1 hour. The candle hadexcellent consistency, being sufficiently firm to hold itself up in atapered candle form.

Example 4 ETPA from C₂₄ Branched-Chain Alcohol

This example shows that a clear, hard gel can be made with an ETPAsynthesized from a branched alcohol having a chain size of 24 carbons.

An ETPA was synthesized according to the procedure described in Example3, using the reactants as identified in Table 5. The resultant ETPAgellant had a softening point of 85.2° C. and a viscosity of 20 cP at190° C.

TABLE 5 REACTANTS TO FORM A BRANCHED C₂₄ ALCOHOL-TERMINATED POLYAMIDEReactant % Equivalents Weight % Empol ® 1008 100 64.7 Ethylene Diamine60 4.0 Iso Tetracosanol 40 31.3

A gel was prepared from this ETPA according to the procedure describedin Example 1. As summarized in Table 2, the gel was clear and hard.

Example 5 ETPA from C₁₀ Linear Alcohol

This example shows that an opaque gel in tetradecane is formed when anETPA made form a linear alcohol having a chain length of 10 carbons isused.

The ETPA was synthesized in the manner described in Example 3 using thereactants identified in Table 6. As summarized in Table 2, the ETPA hada softening point of 93.2° C. and a viscosity at 190° C. of 29 cP.

TABLE 6 REACTANTS TO FORM A LINEAR C₁₀ ALCOHOL-TERMINATED POLYAMIDEReactant % Equivalents Weight % Empol ® 1008 100 79.5 Ethylene Diamine65 5.4 n-Decanol 35 15.1

This ETPA was combined with tetradecane to form a gel according to theprocedure of Example 1. The gel was opaque and hard, as summarized inTable 2.

Example 6 ETPA with Moderate C₄ Linear Alcohol Termination

This example shows that an opaque gel in tetradecane is formed when anETPA made from a linear alcohol having a chain length of 4 carbons isused.

With one exception, the ETPA was synthesized in the manner described inExample 3, using the reactants set forth in Table 7. In this Examplehowever, excess butanol was added to the formulation before the vacuumstage, to thereby reduce the acid number to 10-15. As summarized inTable 2, the gel had a softening point of 86.3° C. and a viscosity of 35cP at 190° C.

TABLE 7 REACTANTS USED TO FORM A LINEAR C₄ ALCOHOL-TERMINATED POLYAMIDEReactant % Equivalents Weight % Empol ® 1008 100 86.5 Ethylene Diamine65 5.8 n-Butanol 35 7.7

A gel was made from this ETPA as described in Example 1. The gel wasopaque and soft, and showed syneresis (i.e., “bleeding” of tetradecanefrom the gel), which is undesirable.

Example 7 ETPA from with High C₄ Linear Alcohol Termination

This example shows that a clear gel in tetradecane is formed when anETPA made from a linear alcohol having a chain length of 4 carbons at arelatively high concentration (50% eq.) is used.

An ETPA was synthesized in the manner described in Example 6, againusing excess butanol before the vacuum stage in order to reduce the acidnumber to 10-15. The reactants used to form this ETPA are set forth inTable 8. The product ETPA has a softening point of 77.2° C. and aviscosity of 15 cP at 190° C.

TABLE 8 REACTANTS USED TO FORM A LINEAR C₄ ALCOHOL-TERMINATED POLYAMIDEReactant % Equivalents Weight % Empol ® 1008 100 84.8 Ethylene Diamine50 4.4 n-Butanol 50 10.8

A gel was made using this ETPA, according to the procedure described inExample 1. The gel was clear and hard (see Table 2).

Example 8 ETPA with Low C₁₈ Linear Alcohol Termination

This example shows that there is a lower limit to the alcoholconcentration that can be used in an ETPA, and still obtain atransparent gel therefrom. Below this limit, opaque gels in tetradecaneare formed.

An ETPA was synthesized according to the procedure of Example 3, usingthe reactants identified in Table 9. The ETPA has a softening point of90.4° C. and a viscosity of 47 cP at 190° C.

TABLE 9 REACTANTS USED TO FORM A LINEAR C₁₈ ALCOHOL-TERMINATED POLYAMIDEReactant % Equivalents Weight % Empol ® 1008 100 76.4 Ethylene Diamine75 5.9 Stearyl alcohol 25 17.7

This ETPA was formed into a gel according to the procedure outlined inExample 1. The gel was hard but opaque, as summarized in Table 2.

A second gel was prepared by combining 40 parts of this ETPA with 60parts of mineral oil. These two ingredients were heated untilhomogenous, and then allowed to cool. During the cooling process, a wickwas added to the gelled body, in order to form a candle. The gelled bodywas clear and hard, with a melting point of 110° C. Upon burning, theflame height was 0.5 inches, and the pool size (as defined in Example 3)was 1.25 inches. There was a little coking, but less than the mountobserved with the candle of Example 3. There was no discoloration in theburned area.

Example 9 ETPA from with very High C₂₄ Branched-Chain AlcoholTermination

This example shows that a there is an upper limit to the alcoholconcentration that can be used in a forming an ETPA, and still obtain ahard gel. Above this limit, clear, extremely soft gels in tetradecaneare formed.

An ETPA was synthesized as in Example 1, using the reactants set forthin Table 10. The ETPA was very soft, having a melting point below roomtemperature. The viscosity of the ETPA at 130° C. was 20.5 cP.

TABLE 10 REACTANTS USED TO FORM A BRANCHED C₂₄ ALCOHOL-TERMINATEDPOLYAMIDE Reactants % Equivalents Weight % Empol ® 1008 100 51.5Hexamethylene Diamine 30 3.1 Iso Tetracosanol 70 45.4

A gel was prepared from this ETPA as described in Example 1. The gel wasclear but very soft, as summarized in Table 2.

Example 10 ETPA from Co-Diacid and C₁₈ Linear Alcohol

This example shows that a co-diacid can be added to the ETPA formulationto increase the gel hardness while maintaining clarity.

An ETPA was synthesized as in Example 3, charging the co-diacid beforeheating. The reactants listed in Table 11 were used to form this ETPA.The product had a softening point of 133.5° C. and a viscosity at 190°C. of 26 cP.

TABLE 11 REACTANTS USED TO FORM A LINEAR C₁₈ ALCOHOL-TERMINATEDPOLYAMIDE WITH 10% SEBACIC ACID Reactant % Equivalents Weight % Empol ®1008 90 67.8 Sebacic Acid 10 2.7 Ethylene Diamine 65 5.1 Stearyl alcohol35 24.4

Using the procedure of Example 1, a gel was formed from this ETPA. Thegel was clear and hard, as summarized in Table 2.

TABLE 2 THE PHYSICAL AND GEL PROPERTIES OF ETPAs MADE FROM VARIOUSALCOHOL SIZES AND CONCENTRATIONS Ex. Alcohol Alc. Conc. Soft. Pt.Viscosity 20 wt. % ETPA in No. Chain (% eq.) (° C.) (cP) tetradecane 7 4(linear) 50 77.2   15 @ 190° C. clear, hard gel 6 4 (linear) 35 86.3  35 @ 190° C. opaque, soft gel, syneresis 5 10 (linear) 35 93.2   29 @190° C. opaque, hard gel 1 14, 16 (linear) 50 68.5   44 @ 130° C. clear,soft gel 3 18 (linear) 35 85.7   27 @ 190° C. clear, hard gel 8 18(linear) 25 90.4   47 @ 190° C. opaque, hard gel 10 18 (−10% sebacic) 35133.5   26 @ 190° C. clear, hard gel 2 22 (linear) 60 73.1 36.5 @ 130°C. clear, soft gel 9 24 (branched) 70 ≈RT 20.5 @ 130° C. clear, verysoft gel 4 24 (branched) 40 85.2   20 @ 190° C. clear, hard gel

Example 11 Effect of Alcohol Chain Length on Gel Clarity

This Example shows that the chain length of the alcohol used to preparean ester-terminated polyamide, will have an affect on the clarity of thegel made from that polyamide. This Example further shows that theconcentration of gellant in a hydrocarbon medium will affect the clarityof the gel.

The ester-terminated polyamides of Example Nos. 6 (C₄ linear alcohol), 5(C₁₀ linear alcohol) and 3 (C₁₈ linear alcohol) were dissolved in hottetradecane at concentrations ranging from 10 to 30 wt. % based on thetotal weight of ETPA and tetradecane. Upon cooling, the resulting gelswere evaluated for clarity with the results as set forth in Table 12.

TABLE 12 GEL CLARITY AS A FUNCTION OF GELLANT CONCENTRATION AND THECHAIN LENGTH OF THE ALCOHOL USED TO PREPARE THE GELLANT Wt. % Gellant InTetradecane - Example Alcohol Gellant Mixture Number Chain Length 10 1520 30 6 C₄  Opaque Opaque Opaque Opaque 5 C₁₀ Opaque Opaque OpaqueTranslucent 3 C₁₈ Opaque Clear Clear Clear

The data of Table 12 shows that none of the ETPAs form clear gels at 10wt. % solids. At 15 wt % and 20 wt % gellant using tetradecane, only thestearyl alcohol-terminated polyamide forms clear gels.

Example 12 Effect of Hydrocarbon on Gel Hardness and Clarity

When the ETPAs of Example 11 were used to form gels in decalin, the gelsshowed improved clarity however tended to be softer. The claritybehavior described in Example 11 is essentially reproduced whentetradecane is replaced with isooctane or with PD 23 (a hydrocarbonblend from Witco. Corp., Greenwich, Conn.). In isooctane, a gel tends tobe harder compared to when decalin is used, however softer than whentetradecane is used.

Example 13 ETPA Composition Used for Gelling a Hydrocarbon Solvent

This example shows how an ETPA can be used to produce a clear, hard gelin PD 23 hydrocarbon, where PD 23 is a petroleum distillate made byWitco (Greenwich, Conn.) that has a viscosity of 2.6 cSt at 40° C. and aflash point of 230° F. PD-23 hydrocarbon is used in household productssuch as furniture polishes, household cleaners, liquid candles, and handcleaners.

A gel was prepared from the ETPA made according to Example 3. The gelwas made by heating 20% (by weight) of the ETPA in PD-23 until the ETPAhad dissolved. The solution was allowed to cool and a clear, hard gelwas formed.

Example 14 ETPA Gel with Klearol Hydrocarbon

This example shows how the ETPA prepared as in Example 3 can be used togel a low viscosity, white mineral oil. The mineral oil used wasKlearol® (Witco Corp., Greenwich, Conn.) which has a viscosity of 7-10cSt at 40° C. and a flash point of 310° F. Klearol® mineral oil is usedin personal care products such as cleansing creams, hand cleansers,costume makeup, lipsticks, and hair care products. When gelled with theETPA at 20% solids, the gel was clear and hard.

Example 15 ETPA Gel with Kaydol Hydrocarbon

This example shows how the ETPA prepared as in Example 3 can be used togel a high viscosity, white mineral oil. The mineral oil used wasKaydol®, which has a viscosity of 64-70 cSt at 40° C., a flash point of430° F. and is available from Witco Corp. Kaydol® mineral oil is used inbath oil, suntan oil, moisturizing creams, and foundation makeup. Whengelled with the ETPA at 30% solids, the gel was clear and hard.

Example 16 ETPA Gel with a Monofunctional Ester Solvent

This example shows how the ETPA prepared as in Example 3 can be used togel a mono-functional ester. The ester was a C₁₂₋₁₅ alkyl benzoatecalled Finsolv^(D) TN, made by Fintex (Elmwood Park, N.J.). When gelledwith the ETPA at 10% solids, the gel was clear and hard.

Example 17 ETPA gel with a Monofunctional Ester Solvent

This example shows how the ETPA prepared as in Example 3 can be used togel a mono-functional ester. The ester was isopropyl isostearate(Unimate IPIS, made by Union Camp, Wayne, N.J.). When gelled with theETPA at 20% solids, the gel was clear and hard.

Example 18 ETPA Gel with a Multifunctional Ester Solvent

This example shows that a multi-functional ester can be gelled with theETPA prepared as in Example 3. The ester was castor oil. When combinedwith the ETPA at 20% solids, a clear, hard gel was formed.

Example 19 ETPA Gel with Terpene Hydrocarbon Solvent

This example shows that a terpene hydrocarbon solvent can be gelled withan ETPA. An ETPA was prepared using the procedure of Example 8. Theresultant ETPA was combined with limonene at 20% solids to yield aclear, firm gel.

Example 20 Comparative Example

In this comparative example, an ETPA was made by first synthesizing apolyamide from Empol 1008 hydrogenated dimer (Henkel Corp. Ambler, Pa.)and EDA resulting in a polyamide with an amine number of 3 and asoftening point of 115° C. 100 g of this polyamide was heated undernitrogen with 66 g of Empol 1008 at 230° C. for 50 minutes. The mixturewas cooled to 110° C. and 30 g of ethanol and 2 ml of HCl were added.The mixture was heated under reflux conditions and the temperature wasallowed to reach 230° C. The acid number was checked periodically andethanol was added (at 110° C.) until the acid number was less than 30.At 230° C., vacuum was held on the mixture for 0.5 h and the ETPA waspoured. The resultant ETPA had an acid number of 25 and a softeningpoint of 80° C.

The ETPA was combined with tetradecane at 20% and heated until the ETPAdissolved. Upon cooling, an opaque, soft gel formed that showedsyneresis.

Example 21 Comparative Example

This comparative example repeats Example 20, however the esterificationwas done at much lower temperatures. The polyamide described in Example20 (softening point=115° C.) was heated under reflux with Empol 1008 at230° C. in the same proportions as in Example 20 for 50 min. Thismixture was then cooled to 25° C. and ethanol and HCl were added in thesame proportions as in Example 20. The mixture was heated under refluxat 80-85° C. for eight hours and the excess ethanol was removed in anitrogen stream at 100° C. The resultant product had an acid number of17 and a softening point of 83° C. This material at 20% level was thenheated in tetradecane until dissolved. After the mixture cooled, anopaque, soft gel formed that showed synersis.

Example 22 Comparative Example

This comparative example shows that the ETPA made in Example 21 iscapable of thickening linseed oil, a component of alkyd paints. The ETPAmade in Example 21 at 10% level was heated in linseed oil untildissolved. Upon cooling, an opaque, thickened product was formed.

Example 23

This example shows that the ETPA made according to the present methodthickens linseed oil. The ETPA made in Example 3 at 10% level was heatedin linseed oil until dissolved. Upon cooling, an opaque, thickenedproduct was formed.

Example 24

This example shows that an ETPA can be used to gel an oil-based mixturewith an active ingredient. 10 g of the ETPA prepared as in Example 8 washeated in 15 g methyl salicylate, 4 g menthol (active ingredient), and21 g of KAYDOL (white mineral oil) until the ETPA was dissolved. Whenthe solution cooled, a clear, firm gel was formed.

Example 25 Candle Preparation

This Example demonstrates that an ETPA gellant can be used to make aclear candle. The candle was prepared by combining 60 parts Drakeol® 7mineral oil (from Penreco, a division of Pennzoil Products Company,Karns City, Pa.) and 40 parts of the ETPA prepared in Example 8, andheating the combination to about 100° C. until a clear, visuallyhomogeneous solution is obtained. The hot mixture was then poured into ashallow dish that contains a wick. Upon cooling, a clear, freestandingcandle was formed. The candle did not emit smoke when lit, and nodiscoloration was observed after burning.

Throughout the present specification, where gellants or reactionmixtures are described as including or comprising specific components ormaterials, it is contemplated by the inventors that the gellants orreaction mixtures may alternatively consist essentially of, or consistof, the recited components or materials. Accordingly, throughout thepresent disclosure any described composition (gellant or reactionmixture) of the present invention can consist essentially of, or consistof, the recited components or materials.

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiments disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the appended claims.

Example 26 Preparation of Clear Pillar Candle

An ETPA having the composition and properties as shown in Table 13 wasprepared according to the procedure of Example 1.

TABLE 13 COMPOSITION AND PROPERTIES OF ETPA ETPA Parameter 76% dimeracid (Empol ™ 1008), 6% Ethylene Composition (wt. %) diamine 18% stearylalcohol (Alfol ™ 18) color, Gardener 1-3 softening point (° C.) 93-98visc. @ 160° C. (cPs) 110-160 acid/amine numbers 14-10/<1

This ETPA (of Table 13) was used to prepare a candle having thecomposition indicated in Table 14 below. The candle was prepared bycombining the indicated ingredients (except fragrance) and heating themat 100-110° C. in a beaker with stirring. After the ETPA dissolved, thesolution was cooled to 80° C. and the fragrance was added. The solutionwas then poured into a two-piece plastic mold containing a wick. Aftercooling, the mold was removed to provide a clear, free standing candle.

TABLE 14 COMPOSITION OF ETPA-BASED CANDLE Ingredient wt. % Supplier ETPA40.00 Union Camp (Wayne, NJ) Mineral Oil (Drakeol ® 7) 54.85 Penreco(Houston, TX) Pylakrome ™ Red 0.10 Pylam Products (Tempe, AZ) (1% inmineral oil) D&C Violet #2 0.05 Pylam Products (Tempe, AZ) (0.1% inmineral oil) Fragrance 5.00 BBA (Montvale, NJ)

The candle of Table 14 was evaluated and found to have thecharacteristics set forth in Table 15 below.

TABLE 15 BURNING PROPERTIES OF ETPA-BASED CANDLE Property color (lightyellow 1-10 dark yellow) 2-3 clarity (clear 1-10 opaque) 2-3 smoking(when lit/during burning/after burning none intensity of flame(initial/1h/2h/4h/6h) bright color of flame (initial/1h/2h/4h/6h) brightyellow height of flame (initial/1h/2h/4h/6h) 1 in. size of pool,diameter (1h/2h/4h/6h) 1.25/1.25/1.25/1.5 in. color of pool(1h/2h/4h/6h) good/good/slight yellow/ slight yellow weight loss(1h/2h/4h/6h) 3/7/13/20%

Example 27 Comparative Examples of Candle Preparation

Two examples of existing candle technology were compared with theETPA-based clear candle. Table 16 lists the properties andcharacteristics of a ETPA-based candle versus a Geahlene™ (Penreco,Houston, Tex.) based candle and a paraffin based candle. Geahlene®contains Kraton® rubber. The ETPA candle is free standing and clear. Incontrast, the Geahlene® based candle is clear but not free standing, andthe paraffin based candle is free standing however opaque (not clear).In addition, the burning characteristics of the ETPA candle are betterthan the Geahlene™ candle with respect to smoking and flame height, andare better than the paraffin candle with respect to weight loss(longevity).

TABLE 16 COMPARISON OF ETPA CANDLE VERSUS GEAHLENE AND PARAFFIN CANDLESProperty ETPA Geahlene ™ Paraffin clarity clear clear opaque freestanding yes no yes smoking none none some (when lit/burn/after burnintensity of flame bright low very bright (initial/1h/6h) height offlame 1 in. 0.25 in. 1.5 in. (initial/1h/6h) color of pool (1h/6h)good/light tan good/slight good yellow weight loss (1h/2h/4h/6h)3/7/13/20% 2/4/8/13% 7/14/30/43%

Example 28 Preparation of Clear Non-Pillar Candle

A candle was prepared with the ETPA of Example 26 (Table 13), using theprocedure also set forth in Example 26 except the hot ETPA/oil solutionwas poured into a glass jar containing a wick. The candle had thecomposition set forth in Table 17.

TABLE 17 CLEAR NON-PILLAR CANDLE COMPOSITION Ingredient wt. % SupplierETPA (see Table 1) 30.00 Union Camp (Wayne, NJ) Mineral Oil (Drakeol ®7) 64.85 Penreco (Houston, TX) Pylakrome ™ Red 0.10 Pylam Products(Tempe, AZ) (1% in mineral oil) D&C Violet #2 0.05 Pylam Products(Tempe, AZ) (0.1% in mineral oil) Fragrance 5.00 BBA (Montvale, NJ)

Example 29 Clear Pillar Candle with Insect Repellent

A clear, pillar candle having insect repellent (citronella) was preparedusing the ETPA of Example 26 (Table 13) and having the composition shownin Table 18. This candle was prepared according to the procedure ofExample 26.

TABLE 18 COMPOSITION OF CLEAR PILLAR CANDLE WITH INSECT REPELLENTIngredient wt. % Supplier ETPA (see Table 13) 40.00 Union Camp (Wayne,NJ) Mineral Oil (Drakeol ® 7) 46.00 Penreco (Houston, TX) Citronella Oil10.00 BBA (Montvale, NJ) Fragrance 4.00 BBA (Montvale, NJ)

Example 30 Clear Non-Pillar Candle with Insect Repellent

A clear, non-pillar candle having insect repellent (citronella) wasprepared using the ETPA of Example 26 (Table 13), and having thecomposition shown in Table 19. This candle was prepared according to theprocedure of Example 26.

TABLE 19 COMPOSITION OF CLEAR NON-PILLAR CANDLE WITH INSECT REPELLENTIngredient wt. % Supplier ETPA (see Table 13) 30.00 Union Camp (Wayne,NJ) Mineral Oil (Drakeol ® 7) 63.00 Penreco (Houston, TX) Citronella Oil5.00 BBA (Montvale, NJ) Fragrance 2.00 BBA (Montvale, NJ)

Example 31 Clear Gelled Body

A clear, gelled body was prepared using the ETPA of Example 26 (Table13), and having the composition shown in Table 20. This gelled body wasprepared according to the procedure of Example 26.

TABLE 20 COMPOSITION OF CLEAR GELLED BODY Ingredient wt. % Supplier ETPA(see Table 13) 2.00 Union Camp (Wayne, NJ) Mineral Oil (Isopar ™ K)96.00 Exxon (Houston, TX) Fragrance 2.00 BBA (Montvale, NJ)

Example 32 Effect of Candle Composition on Clarity and Smoking

Candles were prepared as described in Example 28, using the ETPAcomposition as given in Table 13. The candle composition was 15 wt. %ETPA, 65 wt. % Drakeol® 7, 10 wt. % fragrance 564-27587 (Bush BoakeAllen. Montvale, N.J.) and 10 wt. % of a performance additive as setforth below in Table 21.

Table 21 shows the results of analyzing candles having variousperformance additives, as set forth in the Table. The candles wereevaluated on the basis of clarity and smoking, where smoking wascharacterized on a scale of 1 to 10, where “1” denotes no smoking and“10” denotes heavy smoking.

TABLE 21 ADDITIVE EFFECT ON SMOKING AND CLARITY Performance AdditiveClarity Smoking Stearic acid opaque 2 Stearyl alcohol opaque 2 Myristicacid clear 2 Myristyl alcohol clear 8 Softigen ® (Hüls) C₁₀-C₁₈triglyceride hazy 10 Neobee ® M5 (Stepan) capric/caprylic triglyceridehazy 4 Drakeol ® 7 opaque 10

The data show that myristyl alcohol improves clarity, however has littleeffect (compared to Drakeol® 7) on smoking. The data also show thatstearic acid and some triglycerides improve smoking performance, butprovide little improvement in clarity (again compared to Drakeol® 7).Myristic acid is shown to improve both smoking performance and clarity,versus Drakeol® 7.

Example 33 Clear Candle Displaying Minimal Smoking

Candles were prepared as described in Example 28, using the ETPAcomposition as given in Table 13. The candle composition was 15 wt %ETPA, 60 wt. % Drakeol® 7, 10 wt. % fragrance 564-27587 (Bush BoakeAllen, Montvale, N.J.) and 5 wt. % of myristic acid. The candle wasclear and displayed little or no smoking.

Example 34 Effect of Wick Size on Smoking

Candles were prepared as described in Example 28, using the ETPAcomposition as given in Table 13. The candle composition was 15 wt. %ETPA, 70 wt. % Drakeol® 7, 10 wt. % fragrance 564-27587 (Bush BoakeAllen, Montvale, N.J.) and 5 wt. % myristic acid.

Table 22 shows the data obtained when candles were prepared above, usingvariously sized wick. As shown in Table 22, a larger wick is preferredin order to minimize the smoking of the candle.

TABLE 22 EFFECT OF WICK SIZE ON SMOKING PERFORMANCES Wick Size SmokingPerformance Small wick (<24 ply) smokes 24 ply smokes 30 ply very littlesmoke Large wick (>30 ply) no smoke

Example 35 Fragrance Compatibility with Mineral Oil

Over 150 blends of various fragrance raw materials and mineral oil wereprepared at 5% and 10% concentrations. The blends had thecharacteristics shown in Table 23, where 1=clear, 2=slightly hazy,3=cloudy, and 4=insoluble.

Gels were then prepared from each of the fragrance materials shown inTable 23, where the gels contained 45 wt. % ETPA (of Table 13), 50 wt. %Drakeol® 7 mineral oil, and 5 wt. % of the fragrance. The vast majorityof the gels were clear and did not show syneresis. However, with thosefragrance raw materials listed in Table 23 that have a double asterisk“**” next to the name of the material, either some cloudiness wasobserved in the gel, and/or the gel displayed syneresis.

TABLE 23 FRAGRANCE COMPATIBILITY WITH MINERAL OIL Material Code*Material Name* 5% 10% 160003A Abbalide IPM 1 1 100320A Adoxal NP 1 1100440A Alcohol C-08 1 1 100480A Alcohol C-10 1 1 100500A Alcohol C-11Undecylic 1 1 100580A Aldehyde C-08 1 1 100620A Aldehyde C-10 1 1100640A Aldehyde C-11 Undecylenic 1 1 100680A Aldehyde C-12 Lauric 1 1100700A Aldehyde C-12 MNA 1 1 100840A Allyl Amyl Glycolate 100860A AllylCaproate 1 1 100900A Allyl Cyclo Hexyl Propionate 1 1 100920A AllylHeptanoate 1 1 100960A Allyl Ionone Extra 1 1 100060A Allyl PhenoxyAcetate 1 4 101064A Amber Core 1 1 101300A Amyl Acetate Primary 1 1101578A Amyl Salicylate 1 1 101920A Anisaldehyde** 3 4 101960A AnisylAcetate 1-2 3 102045A Anther 1 1 110015A Bacdanol 1 1 110480A BenzylAcetate** 1 1 110515A Benzyl Alcohol** 3 4 110550A Benzyl Benzoate 1 1110600A Benzyl Iso Butyrate 1 1 110720A Benzyl Propionate 1 1 110738ABenzyl Salicylate 1 1 111111A Boisvelone 1 1 111555A Butyl Butyrate 1 1111615A Butyl Cinnamic Aldehyde 1 1 111785A Butyl Iso Valerate** 2 3120410A Carbitol 3 4 120060A Camphor Powder 10%/20% IPM 1 1 120815ACedarleaf Oil American 2 3 120920A Cedrenol 1 1 120960A Cedryl AcetateLiquid 1 1 121700A Cinnamic Alcohol 3 4 121740A Cinnamic Aldehyde 4 4121900A Cinnamyl Acetate 2 2 122018A Cistulate 1 1 122060A Citral CP 2 3122100A Citralva 1 1 122320A Citronellene Lactone 1 1 122356ACitronellol 750 1 1 122410A Citronellyl Acetate A 1 1 123320A Coumarin10% BB 1 1 123440A Cresyl Methyl Ether, Para 1 1 123680A CyclamenAldehyde 1 1 123725A Cyclocitrenellene Acetate 1 1 123754A CyclohexylSalicylate 1 1 130007A Damascone Alpha 1 1 130280A Diethyl Malonate 4 4130405A Dihydro Eugenol 1 1 130420A Dihydro Myrcenol 1 1 130428A DihydroMyrcenyl Acetate 1 1 130418A Dihydrolinalool 1 1 130435ADihydroterpineol 1 1 130560A Dimethyl Benzyl Carbinyl Acetate 1 1130580A Dimethyl Benzyl Carbinyl Butyrate 2 3 130700A Dimethyl Sulfide**1 1 130720A Dimetol 1 1 130958A Dynascone 10 4 4 140220A Ethyl AcetoAcetate 4 4 140480A Ethyl Cinnamate 1 1 140840A Ethyl Iso Valerate 1 1140660A Ethyl Maltol 10% BB 2 3 100760A Ethyl Methyl Phenyl Glycidate 44 140795A Ethyl Safranate** 3 3 140860A Ethyl Vanillin 10% BB** 1 1-2140680A Ethyl-2-methyl Butyrate 1 1 140880A Ethylene Brassilate 1 1140920A Eucalyptol 1 1 140980A Eugenol 3 3 141146A Exolide 1 1 150002AFarnesol Synthetic 1 1 150023A Fenchyl Acetate 1 2 150025A FenchylAlcohol 1 1 150168A Firbalsam Oliffac abs. 10%/20% IPM 3 3-4 150200A FirNeedle Oil Siberian 1 1 150322A Florosa/Florol 1 1 150560A Fructone 1 1150570A Fruitate 1 1 160310A Geraniol 8020 1 1 160515A Geranyl Acetate 11 161170A Gyrane 1 2 170060A Hedione 1 1 170080A Helional 3 3 170100AHeliotropine 10%/20% IPM 1 1 170228A Herboxane 1 1 170240A Hercolyn 1 1170380A Hexenol, CIS-3 1 1 170420A Hexenyl Acetate, CIS-3 1 1 170442AHexenyl Iso Butyrate, CIS-3 1 1 170520A Hexenyl Salicylate, CIS-3 1 1170600A Hexenyl Acetate Alpha 1 1 170620A Hexenyl Cinnamic Aldehyde 1 1170660A Hexyl Salicylate** 1 1 170680A Hexylene Glycol 4 4 170940AHydroxycitronellal Pure 55 3 3 171100A Hydroxy phenyl butanone 10% BB 34 180040A Indol 10%/20% IPM** 1 1 180120A Ionone Alpha Refined (800 UC)1 1 101380A Isoamyl-N-Butyrate 1 1 111140A Isoborneol 10%/20% IPM 1 1111180A Isobornyl Acetate 1 1 111215A Isobornyl cyclohexanol 10%/20% IPM1 1 123720A Isocyclocitral 1 1 250072A Isopar M 1 1 251840A IsopropylMyristate 1 1 190323A Jasmopyrane 1 1 210352A Lavandin Oil Grosso Pure 44 211240A Lilestralis 1 1 211580A Linalool Oxide 1 1 211520A LinaloolSynthetic 1 1 211620A Linalyl Acetate Synthetic 1 1 211920A Lyral 2 2220050A Magnol** 1 1 220055A Majantol 1 1 220089A Malusate 1 1 220190AManzanate 1 1 220305A Melusat 1 1 220504A Methoxy Melonal 1 1 220520AMethoxycitronellal 1 1 220600A Methyl Anthranilate 1 1 220660A MethylBenzoate 1 1 220720A Methyl Chavicol 1 1 220740A Methyl cinnamate10%/20% IPM 1 1 221076A Methyl Ionone Gamma Supreme (600 UC) 1 1 220860AMethyl Iso Eugenol 1 1 221300A Methyl Salicylate 1 1 100780A NonalactoneGamma 1 1 111081A Octahydro Coumarin 1 2 240812A Orange TerpenesDistilled 1 1 241120A Osyrol 1 1 250707A Peranat 1 1 250892A Phenoxanol1 1 250900A Phenoxy Ethanol 3 4 250920A Phenoxy Ethyl Iso Butyrate 1 1250940A Phenyl Acetaldehyde 4 4 251020A Phenyl Ethyl Acetate 1 1 251068APhenyl Ethyl Alcohol 3 4 251320A Phenyl Propyl Alcohol 3 4 251739APrecyclmone B 1 1 251740A Prenyl Acetate 1 1 270460A Rosalva 1 1 280720ASternone 1 1 251280A Styralyl Acetate 1 1 290320A Terpineol Alpha 1 1290320A Terpinyl Acetate 1 1 290448A Tetrahydro Allo Ocimenol 1 1290500A Tetrahydro Myrcenol 1 1 290840A Tetralide 10%/20% IPM** 1 1230602A Trimethyl Hexyl Acetate, 3-5-5 1 1 291060A Triplal 1 1 291149AUltravanil 4 4 300007A Undecalactone Gamma 1 1 300011A Undecvertol 1 1310340A Vanillin 10% BB 3 4 37016OU Veilex #1 1 1 37014OU Veilex #2 1 137013OU Veilex #3 1 1 310480A Verdox 1 1 310500A Verdyl Acetate 1 1310505A Verdyl Propionate 1 1 310620A Vertenex 1 1 310655A Vertocinth 11 310660A Vertofix Coeur 1 1 *Fragrance materials were obtained fromBush Boake Allen (BBA), Montvale, NJ, and are designated with theMATERIAL CODE and name used by BBA.

Of the 11 fragrance raw materials that are identified by a doubleasterisk in Table 23, four are incompatible with mineral oil and theother seven are compatible at 5% and 10% concentration. This indicatesthat some of the raw materials that are compatible with the mineral oilare incompatible with the ETPA. There are also raw materials that areincompatible with mineral oil but are still compatible in the ETPA gelformulation, indicating that these raw materials are solubilized by theETPA. This result indicates that in order for a fragrance component tobe incompatible with an ETPA gel formulation, the material must beincompatible with both the mineral oil and the ETPA at the relativeconcentrations of these materials in the gel formulation.

Example 36

An air freshener was prepared by combining 45 wt. % of ETPA prepared asin Example 3, 35 wt. % Isopar® M (Exxon Chemicals, Houston, Tex.) and 20wt. % fragrance 564-2432 (BBA, Montvale N.J.). The air freshener wascolored by the addition of 0.1% of a 0.2% solution of Pylaklor® Blue(Pylam Products, Tempe Ariz.) dissolved in mineral oil. The result was acrystal clear, hard gel, which was firm enough to stand and hold itsshape without a rigid container.

Example 37 Inventive Air Freshener Containing ETPA

A gel was prepared by heating 20 wt. % of ETPA prepared as in Example 3and 80 wt. % limonene to form a homogenous mixture. While cooling, 6 gof the (still molten) gel was poured into an aluminum pan which wascovered until the gel had cooled to room temperature. After reachingroom temperature, the pan+gel was weighed, and then reweighedperiodically to determine the time dependence of weight loss due toevaporation of the limonene. The percent weight loss as a function oftime is shown in FIG. 2, where the percent weight loss was calculatedbased on the initial amount of fragrance in the 6 grams of gel.

B. Comparative Air Freshener Containing Polyamide

A gel was prepared by heating 70 wt. % Uni-Rez® 2652 adhesive gradepolyamide resin (Union Camp, Wayne, N.J.) and 30 wt. % limonene to forma homogeneous mixture. This gel has a lower concentration of limonenethan the gel prepared in Section A with ETPA because when additionallimonene was added to Uni-Rez® 2652 polyamide, the polyamide did notstay in solution. While cooling, 6 g of the (still molten) gel waspoured into an aluminum pan which was covered until the gel had cooledto room temperature. After reaching room temperature, the pan+gel wasweighed, and then reweighed periodically to determine the timedependence of weight loss due to evaporation of the limonene. Thepercent weight loss as a function of time is shown in FIG. 2, where thepercent weight loss was calculated based on the initial amount offragrance in the 6 grams of gel.

C. Control

An aluminum pan as used in Sections A and B above was charged with 4.8 gof limonene. The percent weight loss (based on the initial weight oflimonene) as a function of time is plotted in FIG. 2.

FIG. 2 shows that limonene is released from a limonene/ETPA gel at aboutthe same rate as limonene evaporates from neat limonene. Also, FIG. 2shows that essentially all of the limonene originally present in thelimonene/ETPA gel is released. In contrast, limonene is released at arelatively slow rate from limonene/Uni-Rez® polyamide, and is onlyincompletely released even after 20 days.

Example 38

The experiment described in Example 37 was repeated, with the changethat limonene was replaced with a different fragrance material, namelyhexyl acetate. The weight loss data is shown in FIG. 3, and essentiallyrepeats the result observed for limonene. Thus, hexyl acetate is slowlyand incompletely released from Uni-Rez® 2652 polyamide resin, whilebeing rapidly and completely released from ETPA.

Example 39

A. An air freshener composition was prepared by combining 15 wt. % ofthe ETPA of Example 8, and 45 wt. % Isopar® M (C₁₃-C₁₄isoparaffin,Exxon, Houston, Tex.) and heating the mixture to 100° C. Then 20 wt. %Isopar® L. (C₁₁-C₁₃isoparaffin, Exxon, Houston, Tex.), and 20 wt %fragrance 524-27901 (BBA, Montvale, N.J.) were added, where the wt. %values are based on the entire weight of the composition. Thecomposition was stirred until it became homogeneous and, prior tocooling, 148.26 g of the molten gel was poured into a container weighing71.12 g, and sealed with a cap weighing 4.59 g. The container was placedinto a holder weighing 79.92 g, so that the initial weight of the entirearticle was 303.69 g. The article was reweighed periodically, and theweight lost divided by the initial weight (times 100) is plotted as afunction of time in FIG. 4.

B. An air freshener composition was prepared by combining 15 wt. % ofthe ETPA polymer of Example 8, and 65 wt. % Isopar® M(C₁₃-C₁₄isoparaffin, Exxon, Houston, Tex.), and heating the mixture to100° C. Then 20 wt. % fragrance 524-27901 (BBA, Montvale, N.J.) wereadded, where the wt. % values are based on the entire weight of thecomposition. The composition was stirred until it became homogeneousand, prior to cooling, about 150 g of the molten gel was poured into acontainer to form an article. The article was weighed periodically, andthe weight lost divided by the initial weight (times 100) is plotted asa function of time in FIG. 4.

Example 40

An air freshener was prepared by combining 63 wt. % of the ETPA resinprepared in Example 8 and 25.6 wt. % Isopar® M (C₁₃-C₁₄isoparaffin,Exxon, Houston, Tex.) and heating this mixture to 100° C. with stirringuntil uniform. The temperature was reduced to 90° C., and then 10 wt. %fragrance 321-28856 (BBA, Montvale, N.J.), 1 wt. % D&C yellow #10 and0.4 wt. % D&C green #5 dye were added (Pylam Products, Tempe Ariz.).After mixing until uniform, the mixture was poured into a star-shapedmold. After the gel had almost completely set up, it was coated with amixture of 20 wt. % Uni-Rez 2620 polyamide resin (Union Camp, WayneN.J.) dissolved in n-propanol.

Example 41

An air freshener was prepared by combining 63 wt. % of the ETPA resinprepared in Example 8 and 26.8 wt. % Isopar® M (C₁₃-C₁₄isoparaffin,Exxon, Houston, Tex.) and heating this mixture to 100° C. with stirringuntil uniform. The temperature was reduced to 90° C., and then 10 wt. %fragrance 522-28855 (BBA, Montvale, N.J.), and 0.2 wt. % Pylakrome Red(Pylam Products, Tempe Ariz.) were added. After mixing until uniform,the mixture was poured into a heart-shaped mold. After the gel hadalmost completely set up, it was coated with a mixture of 20 wt. %Uni-Rez 2620 polyamide resin (Union Camp, Wayne N.J.) dissolved inn-propanol.

Example 42

A fragrance stick was prepared by combining 40 wt. % of ETPA as preparedin Example 3 with 45 wt. % Drakeol® 7 mineral oil (Penreco, a divisionof Pennzoil Products Company, Kearns City, Pa.), heating the mixtureuntil homogeneous (about 100° C.) and then adding 15 wt. % fragrance141-27669 (BBA, Montvale, N.J.). Upon cooling, the composition had acrystal-clear appearance with a stick-like consistency which was fairlyhard. Upon application to the skin, the residue had a somewhat greasyfeel. Also, the amount of material that was applied to the skin using areasonable amount of force was somewhat less than desired, i.e., thepay-off was too slow.

Example 43

A fragrance stick was prepared by combining 30 wt. % of ETPA as preparedin Example 3 with 55 wt. % Drakeol® 7 mineral oil, heating the mixtureuntil homogeneous (about 100° C.) and then adding 15 wt. % fragrance141-27669 (BBA, Montvale, N.J.). Upon cooling, the composition had acrystal-clear appearance with a stick-like consistency which was not ashard as the stick of Example 42. Upon application to the skin, theresidue had a somewhat greasy feel, however the pay-off was excellent.

Example 44

A fragrance gel was prepared by combining 20 wt. % of ETPA as preparedin Example 3 with 65 wt. % Drakeol® 7 mineral oil, heating the mixtureuntil homogeneous (about 100° C.) and then adding 15 wt. % fragrance141-27669 (BBA, Montvale, N.J.). The fragrance gel had the consistencyof gelatin, however when a finger was dipped into the gel, the gelslightly melted and left a residue on the finger. This product would besuitably placed into a container. Upon application to the skin, theresidue had a greasy feel.

Example 45

A fragrance gel was prepared by combining 20 wt. % of ETPA as preparedin Example 3 with 65 wt. % Isopar® M paraffins, heating the mixtureuntil homogeneous (about 100° C.) and then adding 15 wt. % fragrance141-27669 (BBA, Montvale. N.J.). The fragrance gel had the consistencyof gelatin, however when a finger was dipped into the gel, the gelslightly melted and left a residue on the finger. This product would besuitably, placed into a container. Upon application to the skin, theresidue did not have a greasy feel.

Example 46

A fragrance stick was prepared by combining 30 wt. % of ETPA as preparedin Example 3 with 55 wt. % Isopar® M paraffins, heating the mixtureuntil homogeneous (about 100° C.) and then adding 15 wt. % fragrance141-27669 (BBA, Montvale, N.J.). Upon cooling, the composition had acrystal-clear appearance with a hard, stick-like consistency which wasnot as hard as the stick of Example 42. Upon application to the skin,the residue dried quickly and did not feel greasy. Also, the pay-off wasexcellent and the composition was crystal clear.

Example 47

A fragranced soft gel was prepared by combining 20 wt. % of ETPA asprepared in Example 3 with 55 wt. % Isopar® M paraffins, heating themixture until homogeneous (about 100° C.) and then adding 25 wt. %040-27273 fragrance (BBA, Montvale N.J.). The gel solidified at about35° C. to form a soft composition that displayed syneresis.

Example 48

A fragranced soft gel was prepared by combining 30 wt. % of ETPA asprepared in Example 3 with 45 wt. % Isopar® M paraffins, heating themixture until homogeneous (about 100° C.) and then adding 25 wt. %040-27016 fragrance (BBA, Montvale N.J.). The gel solidified at 45° C.to form a stick having a desirably firm consistency, which did notdisplay syneresis, and was almost crystal clear.

Example 49

A fragranced soft gel was prepared by combining 30 wt. % of ETPA asprepared in Example 3 with 45 wt. % Isopar® M paraffins, heating themixture until homogeneous (about 100° C.) and then adding 25 wt. %040-27016 fragrance (BBA, Montvale N.J.). The gel solidified at 45° C.to form a stick which had a desirably firm consistency, did not displaysyneresis, was almost clear and had good pay-off.

Example 50

A fragranced soft gel was prepared by combining 30 wt. % of ETPA asprepared in Example 3 with 45 wt. % Isopar® M paraffins, heating themixture until homogeneous (about 100° C.) and then adding 25 wt. %640-22203 fragrance (BBA, Montvale N.J.). The gel solidified at 45° C.to form a stick with a desirably firm consistency which was also cloudy.This soft gel used a different fragrance than the soft gel of Example49, demonstrating the selection of the fragrance is important indetermining whether a clear or cloudy gel will be produced.

Example 51

A fragranced soft gel was prepared by combining 30 wt. % of ETPA asprepared in Example 3 with 55 wt. % Isopar® M paraffins, heating themixture until homogeneous (about 100° C.) and then adding 15 wt. %141-27669 fragrance (BBA, Montvale N.J.). The gel solidified at 50-55°C. to form a stick which had a desirably firm consistency and excellentrub-off properties onto skin. The stick was clear.

Example 52

A insect stick was prepared by combining 45 wt. % of ETPA as prepared inExample 3 with 39.5 wt. % Isopar® M (Exxon Chemicals, Houston, Tex.), 15wt. % DEET (Morflex, Greensboro, N.C.), 0.5 wt. % fragrance 564-24392(BBA, Montvale, N.J.) and 0.5% of a 0.2 wt. % solution of Pylakrome Blue(Pylam Products, Tempe Ariz.) in mineral oil. These ingredients weretaken to elevated temperature (about 100° C.) and stirred until ahomogeneous mixture resulted. Upon cooling, the composition had a clearappearance with a stick consistency, which could be rubbed onto the skinor other surface to provide a thin film with insect-repellingproperties.

Example 53

An insect stick was prepared by combining 45 wt. % of ETPA as preparedin Example 3 with 53 wt. % Isopar® (Exxon Chemicals, Houston, Tex.) 1wt. % Prallethrin 90% (McLaughlin Gormely King Company, Minneapolis,Min.) and 1 wt. % fragrance 564-24392 (BBA, Montvale, N.J.). Theseingredients were taken to elevated temperature (about 100° C.) andstirred until a homogeneous mixture resulted. Upon cooling, thecomposition had a clear appearance with a stick consistency, which couldbe rubbed onto a surface (such as the floor or cupboard) to provide athin film with insect-killing properties.

Example 54 Sunscreen Composition

A 250 mL beaker was charged with 4.0 g octyl dimethylaminobenzoate (CASRegistry No. 21245-02-3), 8.0 g octyl salicylate, 6.0 g PD-23hydrocarbon oil (Witco), 4.0 g isopropyl myristate (Union Camp Corp.,Unimate tradmark) and 11.10 g ester-terminated polyamide (ETPA). Themixture was heated to 90° C. until homogeneous. Upon cooling, a clear,firm sunscreen-containing gel was formed.

The gel was combined with 3.0 g cyclomethicone (a silicon oil 345) and8.0 g Klearol mineral oil, and the mixture heated to 90° C. to form ahomogeneous liquid. Upon cooling, a clear, firm gel formed.

The gel was combined with an additional 1 g of cyclomethicone, 3 dropsof potpouri fragrance, and 15.0 g Klearol oil. This mixture was heatedto about 94° C. to form a homogeneous liquid, which upon cooling formeda clear firm gel. A 33.1 g portion of this clear firm gel was combinedwith 3.0 g cyclomethicone and 9.0 g Klearol oil, heated to homogeneityand then allowed to cool. The product was slightly cloudy, had goodglide and a nice feel on the skin. Its composition is 55.4% hydrocarbonoil, 11.5% silicon oil, 13.6% ETPA, 14.7% sunscreen and 4.9% isopropylmyristate.

Example 55 Sunscreen Composition

A flask was charged with 30.0 g Klearol mineral oil, 6.0 gcyclomethicone, 14.0 g isopropyl isostearate and 10.6 g ETPA, for atotal charge of 60 g. This mixture was heated to homogeneity, thencooled to form a gel. A 50 g portion of this gel was combined with 11.5g zinc oxide, the mixture heated and when fluid it was stirred veryquickly (whipped in a blender). Upon cooling, it retained a gelconsistency. This gel was heated and an additional 12.0 g of zinc oxidewere added. After heating, blending and cooling, the product retainedits gel consistency. Another portion of zinc oxide, this time 20.0 g wasadded, and after heating, blending and cooling, the product contained47% zinc oxide and 53% carrier base, and had a good gel-likeconsistency.

Example 56 Gelled Body with Coating

A gel was formed from 45 wt. % of the ETPA of Example 3, 50 wt. %mineral oil (Drakeol® 7 from Penreco) and 5 wt. % fragrance (productnumber 564-24392 from Bush Boake Allen of Montvale, N.J.). A wick wasinserted while the gel cooled, to provide a crystal clear candle withexcellent consistency.

The candle was coated as set forth in Table 24, with the coatingcompositions set forth in Column 1. The Uni-Rez® 2620 and 2970 polyamideresins, the Uni-Rez® R-100 rosin ester and the Micromid® 321 aqueouspolyamide dispersion were obtained from Union Camp Corporation, Wayne,N.J. Epolene® C-16 is a polyethylene wax from Eastman Chemicals. E-1498is a hydrocarbon resin from Exxon Chemicals. In Table 24, “X35-659-22”is a polyamide prepared from 70.14 parts Empol® 1008 hydrogenated dimer,19.76 parts stearic acid, 0.12 parts azelaic acid, 9.02 parts ethylenediamine and 0.95 parts hexamethylene diamine, in a manner analogous tothat described in Example 1.

A candle was dipped into each of the coating composition described incolumn 1 of Table 24, at either 140° C. for neat molten resin or at roomtemperature for the solution coating compositions. Each coating wascharacterized qualitatively in terms of clarity, hardness and whetherthe coating adhered well to the candle.

TABLE 24 COATINGS USED ON GELLED BODIES AND PROPERTIES THEREOF Hard-Coating System Clarity ness Comments X35-659-22 (neat) clear good coatswell Uni-Rez ® 2970 (neat) clear brittle coats well Epolene ® C-16(neat) hazy soft no adhesion E-1498 (neat) clear brittle coats wellUni-Rez ® R-100 (neat) clear brittle coats well 20 wt. % Uni-Rez 2620 inn-propanol clear good coats well (solution) 10 wt. % X35-659-22 inn-propanol clear good coats well (solution) Micromid ® 321 hazy goodcoats poorly Micromid ® 321 - 10 wt. % n-propanol hazy good coats well

Example 57 Clarity Measurement

The clarity test consisted of shining white light through a sample of agiven thickness at room temperature and determining the diffusetransmittance and the total transmittance for the sample. The percenthaze for a sample was calculated by

% haze=(diffuse transmittance/total transmittance)×100

Samples were made by melting the substance to be evaluated and pouringthe melt into 50 mm diameter molds. The samples were made at twothicknesses. 5.5±0.4 mm and 2.3±0.2 mm. The compositions identified inTable 25 were evaluated in this manner.

TABLE 25 GELS AND WAXES USED FOR CLARITY MEASUREMENTS SampleManufacturer paraffin wax (CAS 8002-74-2) Aldrich Chemical (Milwaukee,WI) beeswax chips Mangelsen's (Omaha, NE) wax crystals DistlefinkDesigns (Newton, NY) (Frosty White #51212) 50% ETPA X35-879-48¹ UnionCamp (Wayne, NJ) in Drakeol 7 (Penreco) 20% Kraton ® G1650 (Shell)Penzoil (Houston, TX) in Drakeol 7² ¹ETPA from Example 26 ²Example 2from WO 97/08282

The clarity measurements were made on a Hunter Lab Ultrascan SphereSpectrocolorimeter using the following settings: Specular Included: UVoff; Large area of view; Illuminate D65; Observer 10°; and Standardizedfor total transmittance.

The percent haze values for samples prepared as described above aregiven in Table 26. The standard wax (paraffin) used in traditionalcandles had haze values greater than 93% regardless of sample thickness.The Kraton® samples had very low haze values (<15%), where the thickersample had a larger haze value. The thicker Kraton® sample appeared tohave a large number of air bubbles trapped in the sample, which may haveincreased the haze slightly. The ETPA samples had higher haze valuesthan the Kraton® samples (<43%), and appeared to be thickness dependent.However, the surfaces of the ETPA samples appeared to be smudged. Whenthe smudges were removed from the thicker sample, the haze valuedecreased from about 43% to about 5%. Therefore, the clarity of the ETPAsamples is very dependent on the sample having unsmudged surfaces.

TABLE 26 CLARITY MEASUREMENTS ON GELS AND WAXES Sample Thickness (mm) %Haze paraffin wax 2.1 94.2 paraffin wax 5.0 93.3 beeswax 2.2 93.6beeswax 5.2 93.2 wax crystals 2.5 94.3 wax crystals 5.3 94.2 Kraton ®2.1 14.5 Kraton ® 5.8 9.0 ETPA 2.3 27.2 ETPA 6.0 42.9 ETPA (smudgesremoved) 6.0 4.7

Example 58 Rigidity Measurement

The rigidity test consisted of determining the amount of deflection dueto gravity of a given sized sample at room temperature. Samples ofKraton® and ETPA resins as defined in Table 25 were cast into 57×10×3 mmsamples. These samples were then secured on a horizontal surface using aweight, and the deflection angle was measured as shown in FIG. 5. Thedeflection angle (θ) is calculated by measuring x and y, and using theexpression

θ=arctan(x/y)

where θ=0° is defined as no deflection and θ=90° is defined as themaximum deflection.

The observed deflection angle for the Kraton® and ETPA resin samples isgiven in Table 27. The Kraton® sample deflected about 80° while therewas no visible deflection of the ETPA gel sample.

TABLE 27 DEFLECTION ANGLES OF TWO GELS Sample θ (°) Kraton ® 79 = 3 ETPA˜0

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiments disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the appended claims.

What is claimed is:
 1. A composition comprising ester-terminated dimeracid-based polyamide (ETDABP) and at least one bioactive agent, thecomposition having a consistency of a gel, wherein the bioactive agentis selected from the group consisting of anti-fungal agents, hemorrhoidtreatment agents, anti-itching agents, wart-treatment agents,antibiotics and topical analgesics.
 2. A composition comprisingester-terminated dimer acid-based polyamide (ETDABP) and at least onebioactive agent, the composition having a consistency of a gel, whereinthe bioactive agent is selected from the group consisting ofacetylsalicylic acid, acyclovir,6-[3-(1-adamantyl)-4-methoxyphenyl]-2-naphthoic acid, amphotericin B,ascorbic acid, benzoyl peroxide, betamethasone valerate, chloroxylenol,citric acid, clindamycin phosphate, clobetasol propionate, clotrimazole,cyproheptadine, diclofenac, diphenylhydramine hydrochloride, econazole,erthromycin, estradiol, glycolic acid, glycyrrhetinic acid,hydrocortisone, hydroquinone, ibuprofen, ketoconazole, kojic acid,lactic acid, lidocaine hydrochloride, metronidazole, miconazole,miconazole nitrate, octopirox, 5-n-octanoylsalicylic acid, paracetamol,pramoxine hydrochloride, progesterone, retinoic acid, retinol, salicylicacid, superoxide dismutases, terbinafine, thenaldine, α-tocopherol,tolnaftate, trimeprazine, 1,8,10-tripropionyl-9-anthrone, undecylenate,and vitamin D.
 3. A composition comprising ester-terminated dimeracid-based polyamide (ETDABP) and at least one bioactive agent, thecomposition having a consistency of a gel, wherein the bioactive agentis an antibiotic.
 4. The composition of claim 1 wherein the ETDABP isthe reaction product of reactants comprising dimer acid, diamine andmonoalcohol.
 5. The composition of claim 4 wherein the diamine isselected from the group consisting of ethylenediamine,1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane,1,2-diamino-2-methylpropane, 1,3-diaminopentane, 1,5-diaminopentane,2,2-dimethyl-1,3-propanediamine, 1,6-hexanediamine,2-methyl-1,5-pentanediamine, 1,7-diaminoheptane, 1,8-diaminooctane,2,5-dimethyl-2,5-hexanediamine, 1,9-diaminononane, 1,10-diaminodecane,1,12-diaminododecane, diaminophenanthrene,4,4′-methylenebis(cyclohexylamine), 2,7-diaminofluornen, phenylenediamine, adamantane diamine, 2,4,6-trimethyl-1,3-phenylenediamine,1,3-cyclohexanebis(methylamine), 1,8-diamino-p-menthane,2,3,5,6-tetramethyl-1,4-phenylenediamine, diaminonaphthalene and4-amino-2,2,6,6-tetramethylpiperidine.
 6. The composition of claim 4wherein the monoalcohol has the formula R¹—OH, wherein R¹ is ahydrocarbon group.
 7. The composition of claim 1 wherein the ETDABP isprepared by a method comprising reacting x equivalents of carboxylicacid from diacid or a reactive equivalent thereof, y equivalents ofamine from diamine and z equivalents of hydroxyl from monoalcohol or areactive equivalent thereof, wherein at least about 10% of thecarboxylic acid equivalents are from polymerized fatty acid, andmonoalcohol is substantially the only monofunctional reactant used toform the gellant, wherein each of x, y and z is greater than
 0. 8. Thecomposition of claim 7 wherein 0.9≦{x/(y+z)}≦1.1, and 0.1≦{z/(y+z)}≦0.7.9. The composition of claim 1 wherein the ETDABP has the formula (1):

wherein n designates a number of repeating units such that ester groupsconstitute from 10% to 50% of the total of the ester and amide groups;R¹ at each occurrence is independently selected from hydrocarbyl groups;R² at each occurrence is independently selected from a C₂₋₄₂ hydrocarbongroup with the proviso that at least 10% of the R² groups have 30-42carbon atoms; R³ at each occurrence is independently selected from anorganic group containing at least two carbon atoms in addition tohydrogen atoms, and optionally containing one or more oxygen andnitrogen atoms; and R^(3a) at each occurrence is independently selectedfrom hydrogen, C₁₋₁₀ alkyl and a direct bond to R³ or another R^(3a)such that the N atom to which R³ and R^(3a) are both bonded is part of aheterocyclic structure defined in part by R^(3a)—N—R³.
 10. Thecomposition of claim 9 wherein R¹ at each occurrence is independentlyselected from an alkyl or alkenyl group containing at least 4 carbonatoms; R² at each occurrence is independently selected from a C₄₋₄₂hydrocarbon group with the proviso that at least 50% of the R² groupshave 30-42 carbon atoms; and R^(3a) at each occurrence is independentlyselected from hydrogen, C₁₋₁₀alkyl and a direct bond to R³ or anotherR^(3a) such that the N atom to which R³ and R^(3a) are both bonded ispart of a heterocyclic structure defined in part by R^(3a)—N—R³, suchthat at least 50% of the R^(3a) groups are hydrogen.
 11. The compositionof claim 2 wherein the ETDABP is the reaction product of reactantscomprising dimer acid, diamine and monoalcohol.
 12. The composition ofclaim 11 wherein the diamine is selected from the group consisting ofethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane,1,4-diaminobutane, 1,2-diamino-2-methylpropane, 1,3-diaminopentane,1,5-diaminopentane, 2,2-dimethyl-1,3-propanediamine, 1,6-hexanediamine,2-methyl-1,5-pentanediamine, 1,7-diaminoheptane, 1,8-diaminooctane,2,5-dimethyl-2,5-hexanediamine, 1,9-diaminononane, 1,10-diaminodecane,1,12-diaminododecane, diaminophenanthrene,4,4′-methylenebis(cyclohexylamine), 2,7-diaminofluornen, phenylenediamine, adamantane diamine, 2,4,6-trimethyl-1,3-phenylenediamine,1,3-cyclohexanebis(methylamine), 1,8-diamino-p-menthane,2,3,5,6-tetramethyl-1,4-phenylenediamine, diaminonaphthalene and4-amino-2,2,6,6-tetramethylpiperidine.
 13. The composition of claim 11wherein the monoalcohol has the formula R¹—OH, wherein R¹ is ahydrocarbon group.
 14. The composition of claim 2 wherein the ETDABP isprepared by a method comprising reacting x equivalents of carboxylicacid from diacid or a reactive equivalent thereof, y equivalents ofamine from diamine and z equivalents of hydroxyl from monoalcohol or areactive equivalent thereof, wherein at least about 10% of thecarboxylic acid equivalents are from polymerized fatty acid, andmonoalcohol is substantially the only monofunctional reactant used toform the gellant, wherein each of x, y and z is greater than
 0. 15. Thecomposition of claim 14 wherein 0.9≦{x/(y+z)}≦1.1, and0.1≦{z/(y+z)}≦0.7.
 16. The composition of claim 2 wherein the ETDABP hasthe formula (1):

wherein n designates a number of repeating units such that ester groupsconstitute from 10% to 50% of the total of the ester and amide groups;R¹ at each occurrence is independently selected from hydrocarbyl groups;R² at each occurrence is independently selected from a C₂₋₄₂ hydrocarbongroup with the proviso that at least 10% of the R² groups have 30-42carbon atoms; R³ at each occurrence is independently selected from anorganic group containing at least two carbon atoms in addition tohydrogen atoms, and optionally containing one or more oxygen andnitrogen atoms; and R^(3a) at each occurrence is independently selectedfrom hydrogen, C₁₋₁₀ alkyl and a direct bond to R³ or another R^(3a)such that the N atom to which R³ and R^(3a) are both bonded is part of aheterocyclic structure defined in part by R^(3a)—N—R³.
 17. Thecomposition of claim 16 wherein R¹ at each occurrence is independentlyselected from an alkyl or alkenyl group containing at least 4 carbonatoms; R² at each occurrence is independently selected from a C₄₋₄₂hydrocarbon group with the proviso that at least 50% of the R² groupshave 30-42 carbon atoms; and R^(3a) at each occurrence is independentlyselected from hydrogen, C₁₋₁₀alkyl and a direct bond to R³ or anotherR^(3a) such that the N atom to which R³ and R^(3a) are both bonded ispart of a heterocyclic structure defined in part by R^(3a)—N—R³, suchthat at least 50% of the R^(3a) groups are hydrogen.
 18. The compositionof claim 3 wherein the ETDABP is the reaction product of reactantscomprising dimer acid, diamine and monoalcohol.
 19. The composition ofclaim 18 wherein the diamine is selected from the group consisting ofethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane,1,4-diaminobutane, 1,2-diamino-2-methylpropane, 1,3-diaminopentane,1,5-diaminopentane, 2,2-dimethyl-1,3-propanediamine, 1,6-hexanediamine,2-methyl-1,5-pentanediamine, 1,7-diaminoheptane, 1,8-diaminooctane,2,5-dimethyl-2,5-hexanediamine, 1,9-diaminononane, 1,10-diaminodecane,1,12-diaminododecane, diaminophenanthrene,4,4′-methylenebis(cyclohexylamine), 2,7-diaminofluornen, phenylenediamine, adamantane diamine, 2,4,6-trimethyl-1,3-phenylenediamine,1,3-cyclohexanebis(methylamine), 1,8-diamino-p-menthane,2,3,5,6-tetramethyl-1,4-phenylenediamine, diaminonaphthalene and4-amino-2,2,6,6-tetramethylpiperidine.
 20. The composition of claim 18wherein the monoalcohol has the formula R¹—OH, wherein R¹ is ahydrocarbon group.
 21. The composition of claim 3 wherein the ETDABP isprepared by a method comprising reacting x equivalents of carboxylicacid from diacid or a reactive equivalent thereof, y equivalents ofamine from diamine and z equivalents of hydroxyl from monoalcohol or areactive equivalent thereof, wherein at least about 10% of thecarboxylic acid equivalents are from polymerized fatty acid, andmonoalcohol is substantially the only monofunctional reactant used toform the gellant, wherein each of x, y and z is greater than
 0. 22. Thecomposition of claim 21 wherein 0.9≦{x/(y+z)}≦1.1, and0.1≦{z/(y+z)}≦0.7.
 23. The composition of claim 3 wherein the ETDABP hasthe formula (1):

wherein n designates a number of repeating units such that ester groupsconstitute from 10% to 50% of the total of the ester and amide groups;R¹ at each occurrence is independently selected from hydrocarbyl groups;R² at each occurrence is independently selected from a C₂₋₄₂ hydrocarbongroup with the proviso that at least 10% of the R² groups have 30-42carbon atoms; R³ at each occurrence is independently selected from anorganic group containing at least two carbon atoms in addition tohydrogen atoms, and optionally containing one or more oxygen andnitrogen atoms; and R^(3a) at each occurrence is independently selectedfrom hydrogen, C₁₋₁₀ alkyl and a direct bond to R³ or another R^(3a)such that the N atom to which R³ and R^(3a) are both bonded is part of aheterocyclic structure defined in part by R^(3a)—N—R³.
 24. Thecomposition of claim 23 wherein R¹ at each occurrence is independentlyselected from an alkyl or alkenyl group containing at least 4 carbonatoms; R² at each occurrence is independently selected from a C₄₋₄₂hydrocarbon group with the proviso that at least 50% of the R² groupshave 30-42 carbon atoms; and R^(3a) at each occurrence is independentlyselected from hydrogen, C₁₋₁₀alkyl and a direct bond to R³ or anotherR^(3a) such that the N atom to which R³ and R^(3a) are both bonded ispart of a heterocyclic structure defined in part by R^(3a)—N—R³, suchthat at least 50% of the R^(3a) groups are hydrogen.